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Posted to dev@apex.apache.org by Bhupesh Chawda <bh...@datatorrent.com> on 2016/03/10 13:04:43 UTC
Re: Changes to JdbcOutputOperator
Hi All,
Apart from extending the JDBC Output operator (for update, merge and
delete), I am planning the following change to the "*insert*" functionality:
- It was pointed out that - if the incoming POJO has fields which are to
be inserted into a database table, the user should not have to specify any
kind of mapping between POJO columns and database table column names. This
is possible if the POJO field names are same as the db column names.
- Here is what I am planning to do to address this:
- Have a flag which indicates "*No mapping required. Assume same POJO
field names as the DB column names.*"
- If this flag is true, extract DB column names (in addition to the
types, which is done currently) and create getters from POJO based on the
DB column types.
- Use these getters to populate the parametrized "*insert*" query.
Note - Once this is done, the user would not have to specify any field
descriptions. Just the DB table name would be sufficient. This would only
be possible if the DB column names are the same as the field names in the
POJO.
Without this change, "*insert*" will be considered as just another DDL
query like "update" / "delete" / "merge". We accept a parametrized query
and a mapping from the user for POJO field names to DB column names + DB
column types.
Thanks.
Bhupesh
On Wed, Dec 30, 2015 at 12:56 PM, Bhupesh Chawda <bh...@datatorrent.com>
wrote:
> Also, since we are not creating separate operators for insert and
> update/merge, it seems we don't need an abstract class. We can directly
> modify JdbcPOJOOutputOperator.
>
> -Bhupesh
>
> On Wed, Dec 30, 2015 at 11:17 AM, Bhupesh Chawda <bh...@datatorrent.com>
> wrote:
>
>> Also, a note regarding accepting fieldInfo objects:
>>
>> FieldInfo has fields for java type of the column, but not the SQL data
>> type which is needed to set the parameters in the SQL statement. This still
>> needs to be derived from the database (as in insert).
>> In more complex scenarios, as mentioned earlier, this may not always be
>> possible. In this case we have the following options:
>>
>> 1. Accept the SQL data types from the user for the parameters ("?")
>> in a new data structure.
>> 2. Accept the JSON structure as specified earlier.
>> 3. Modify FieldInfo to have an additional optional field which
>> indicates the SQL data type of the parameter ("?")
>>
>> I am planning to go ahead with option 3.
>>
>> Comments?
>>
>> -Bhupesh
>>
>>
>>
>> On Mon, Dec 28, 2015 at 11:26 PM, Chandni Singh <ch...@datatorrent.com>
>> wrote:
>>
>>> Yeah that sounds good.
>>>
>>> Chandni
>>>
>>> On Mon, Dec 28, 2015 at 2:46 AM, Bhupesh Chawda <bhupesh@datatorrent.com
>>> >
>>> wrote:
>>>
>>> > Thanks Chandni for the comments.
>>> >
>>> > Additionally I think, we should do away with constructing the SQL
>>> query in
>>> > the operator. This is because it is only possible in case of simple
>>> insert
>>> > statements. In case a where clause is needed in the insert statement,
>>> we
>>> > cannot construct the SQL easily. If we are accepting a parametrized
>>> query
>>> > from the user for update/merge, why not do the same for insert
>>> statements
>>> > as well? Then the hierarchy would look like:
>>> > - AbstractJdbcPOJOOutputOperator (As suggested)
>>> > -- JdbcPOJOOutputOperator (Takes care of all statements insert, update,
>>> > merge, delete)
>>> >
>>> > We don't need a separate operator for inserts and update/merge.
>>> >
>>> > Thanks.
>>> > -Bhupesh
>>> >
>>> >
>>> > On Mon, Dec 28, 2015 at 3:32 PM, Chandni Singh <
>>> chandni@datatorrent.com>
>>> > wrote:
>>> >
>>> > > 1. FieldInfo, is ultimately a custom object and any user who uses
>>> this
>>> > > operator has to construct an object, populate it and then use it.
>>> We
>>> > are
>>> > > trying to avoid using any custom object and allow any user to use
>>> the
>>> > > operator without writing any extra code; just configuration.
>>> > > FieldInfo is a way to provide configuration in a UI friendly way.
>>> > Providing
>>> > > configuration as JSON is not UI friendly.
>>> > >
>>> > > 2. In case of update / merge, we need what SQL data types that the
>>> > > expression provided by the user would evaluate to. In case of
>>> insert
>>> > we
>>> > > can
>>> > > go and fetch the data types of the columns directly from DB.
>>> However,
>>> > > the
>>> > > same is not possible for custom expressions; "avg(salary)" for
>>> > instance.
>>> > > Ok so here is where you can make a change.
>>> > > - JDBCPojoOutput can be renamed to AbstractJDBCPojoOutpuOperator.
>>> > > - Abstraction is to fetch the type of column.
>>> > > - Add a concrete JDBCPojoInsertOutput that derives the types of
>>> columns
>>> > > directly from DB. Please note that FieldInfo can also provide type of
>>> > > derived column.
>>> > >
>>> > >
>>> > > You mentioned "We are trying to avoid using any custom object and
>>> allow
>>> > any
>>> > > user to use the
>>> > > operator without writing any extra code".
>>> > > This I think is specific to your use case. You can create an
>>> extension of
>>> > > the above which takes JSON blob and creates FieldInfos from it.
>>> > >
>>> > > Chandni
>>> > >
>>> > >
>>> > >
>>> > >
>>> > >
>>> > > On Mon, Dec 28, 2015 at 1:48 AM, Bhupesh Chawda <
>>> bhupesh@datatorrent.com
>>> > >
>>> > > wrote:
>>> > >
>>> > > > Hi Chandni,
>>> > > >
>>> > > > Following are the issues:
>>> > > >
>>> > > > 1. FieldInfo, is ultimately a custom object and any user who
>>> uses
>>> > this
>>> > > > operator has to construct an object, populate it and then use
>>> it. We
>>> > > are
>>> > > > trying to avoid using any custom object and allow any user to
>>> use
>>> > the
>>> > > > operator without writing any extra code; just configuration.
>>> > > > 2. In case of update / merge, we need what SQL data types that
>>> the
>>> > > > expression provided by the user would evaluate to. In case of
>>> insert
>>> > > we
>>> > > > can
>>> > > > go and fetch the data types of the columns directly from DB.
>>> > However,
>>> > > > the
>>> > > > same is not possible for custom expressions; "avg(salary)" for
>>> > > instance.
>>> > > >
>>> > > > Thanks.
>>> > > >
>>> > > > -Bhupesh
>>> > > >
>>> > > >
>>> > > > On Mon, Dec 28, 2015 at 2:57 PM, Chandni Singh <
>>> > chandni@datatorrent.com>
>>> > > > wrote:
>>> > > >
>>> > > > > Hi Bhupesh,
>>> > > > >
>>> > > > > JDBCPojoOutputOperator was written for a demo and therefore it
>>> was
>>> > > marked
>>> > > > > Evolving which is why I had mentioned that you should feel free
>>> to
>>> > > modify
>>> > > > > it.
>>> > > > >
>>> > > > > I think an insert query can be as complex as any other query. It
>>> uses
>>> > > > > FieldInfo because in the app builder it is easy for the user to
>>> > provide
>>> > > > > that instead of JSON String.
>>> > > > >
>>> > > > > Can you please provide specifics about what it is that you find
>>> > > difficult
>>> > > > > to change/implement for providing update/merge/delete support in
>>> > > > > JDBCPojoOutputOperator?
>>> > > > >
>>> > > > > Chandni
>>> > > > >
>>> > > > > On Mon, Dec 28, 2015 at 1:09 AM, Bhupesh Chawda <
>>> > > bhupesh@datatorrent.com
>>> > > > >
>>> > > > > wrote:
>>> > > > >
>>> > > > > > Hi All,
>>> > > > > >
>>> > > > > > It has been pointed out that adding another class for handling
>>> > > update /
>>> > > > > > merge queries would not be a good option.
>>> > > > > >
>>> > > > > > Here are the current implementation details:
>>> > > > > >
>>> > > > > > - We have an existing class: JdbcPOJOOutputOperator which
>>> > accepts
>>> > > a
>>> > > > > list
>>> > > > > > of FieldInfo objects. Each element of this list indicates
>>> the
>>> > > > details
>>> > > > > > (column name, pojo field expression and datatype) of fields
>>> that
>>> > > > need
>>> > > > > > to be
>>> > > > > > inserted. Using this, the operator formulates the insert
>>> query
>>> > in
>>> > > > the
>>> > > > > > setup
>>> > > > > > method and identifies the sql datatypes of these columns
>>> from
>>> > the
>>> > > > > > database
>>> > > > > > using the table name.
>>> > > > > >
>>> > > > > >
>>> > > > > > - Now, coming to the update / merge feature, it is
>>> difficult to
>>> > > > > > formulate the update / merge query in the operator logic
>>> due to
>>> > > the
>>> > > > > > complex
>>> > > > > > structure of these statements. For this reason, we plan to
>>> take
>>> > a
>>> > > > > > parametrized SQL query from the user. This may look like:
>>> > *"update
>>> > > > > table
>>> > > > > > set x = ?, y = ? where z + w > ? and a == 1;"*. Such
>>> statements
>>> > > can
>>> > > > be
>>> > > > > > accepted from the user in addition to a json string which
>>> > > indicates
>>> > > > > the
>>> > > > > > details for the parameters: *column name, the pojo
>>> expression
>>> > and
>>> > > > the
>>> > > > > > sql data type* of the expression. Note that this
>>> information is
>>> > > > > similar
>>> > > > > > to the FieldInfo object, but is a string which can be
>>> configured
>>> > > > > easily
>>> > > > > > by
>>> > > > > > the user. Also note that the data type which is accepted is
>>> the
>>> > > SQL
>>> > > > > data
>>> > > > > > type. Using this info we can populate the parametrized
>>> query and
>>> > > run
>>> > > > > it
>>> > > > > > based on the incoming POJO.
>>> > > > > >
>>> > > > > > The second approach is able to handle all kinds of queries
>>> (insert
>>> > /
>>> > > > > update
>>> > > > > > / merge / delete). However, since we already have the
>>> > > > > > JdbcPOJOOutputOperator, we would like to merge the new
>>> > functionality
>>> > > > into
>>> > > > > > the same class.
>>> > > > > >
>>> > > > > > Here we have the following options:
>>> > > > > >
>>> > > > > > 1. Change the existing class (JdbcPOJOOutputOperator) to the
>>> > > second
>>> > > > > > approach which is more generic and also handles inserts.
>>> > > > > > 2. Add the update/ merge functionality to the existing class
>>> > > without
>>> > > > > > changing the existing functionality. This will have two
>>> > different
>>> > > > ways
>>> > > > > > that
>>> > > > > > insert queries may be handled in the operator.
>>> > > > > > 3. Add another class which extends from
>>> JdbcPOJOOutputOperator
>>> > and
>>> > > > > have
>>> > > > > > the update/merge functionality there. (This is not
>>> recommended.)
>>> > > > > > 4. Any other approach.
>>> > > > > >
>>> > > > > > Please suggest.
>>> > > > > >
>>> > > > > > Thanks.
>>> > > > > >
>>> > > > > > -Bhupesh.
>>> > > > > >
>>> > > > > >
>>> > > > > > On Mon, Dec 14, 2015 at 11:04 AM, Chandni Singh <
>>> > > > chandni@datatorrent.com
>>> > > > > >
>>> > > > > > wrote:
>>> > > > > >
>>> > > > > > > No I don't think we are restricting Malhar to just abstract
>>> > > classes.
>>> > > > > > > Whenever they are couple of use cases that we see quite
>>> often, we
>>> > > add
>>> > > > > > > concrete implementations.
>>> > > > > > >
>>> > > > > > > For eg. FileLineInputOperator which is a concrete
>>> implementation
>>> > of
>>> > > > > > > AbstractFileInputOperator. FSSliceReader is an example as
>>> well.
>>> > > > > > >
>>> > > > > > > In AbstractJdbcOutputOperator case there hasn't been such
>>> common
>>> > > > > > > insert/update query.
>>> > > > > > >
>>> > > > > > > Also if you look at the example I provided, it is very
>>> simple to
>>> > > > > provide
>>> > > > > > a
>>> > > > > > > concrete implementation.
>>> > > > > > >
>>> > > > > > > If you would like to change JdbcPOJOOutputOperator to work
>>> for
>>> > > > > > > "UPDATE/MERGE" then please go ahead.
>>> > > > > > >
>>> > > > > > > Chandni
>>> > > > > > >
>>> > > > > > > On Sun, Dec 13, 2015 at 8:47 PM, Bhupesh Chawda <
>>> > > > > bhupesh@datatorrent.com
>>> > > > > > >
>>> > > > > > > wrote:
>>> > > > > > >
>>> > > > > > > > I see. So, just to understand more, do we plan to keep
>>> Malhar
>>> > > > > > restricted
>>> > > > > > > to
>>> > > > > > > > the base functionality (as in abstract classes)? And put
>>> the
>>> > > > > > > configuration
>>> > > > > > > > aspect / concrete implementations in apps that use these
>>> > > operators?
>>> > > > > > > >
>>> > > > > > > > Thanks.
>>> > > > > > > > Bhupesh
>>> > > > > > > >
>>> > > > > > > > On Sat, Dec 12, 2015 at 5:43 AM, Chandni Singh <
>>> > > > > > chandni@datatorrent.com>
>>> > > > > > > > wrote:
>>> > > > > > > >
>>> > > > > > > > > Hi,
>>> > > > > > > > >
>>> > > > > > > > > Here is an example of doing Upsert with JDBC:
>>> > > > > > > > >
>>> > > > > > > > >
>>> > > > > > > >
>>> > > > > > >
>>> > > > > >
>>> > > > >
>>> > > >
>>> > >
>>> >
>>> https://github.com/chandnisingh/Malhar/blob/examples/apps/jdbc/src/main/java/com/datatorrent/jdbc/JdbcWriter.java
>>> > > > > > > > >
>>> > > > > > > > > Thanks,
>>> > > > > > > > > Chandni
>>> > > > > > > > >
>>> > > > > > > > > On Fri, Dec 11, 2015 at 11:19 AM, Chandni Singh <
>>> > > > > > > chandni@datatorrent.com
>>> > > > > > > > >
>>> > > > > > > > > wrote:
>>> > > > > > > > >
>>> > > > > > > > > > The operators are under Malhar/lib/db/jdbc.
>>> > > > > > > > > >
>>> > > > > > > > > > Here is one of them:
>>> > > > > > > > > >
>>> > > > > > > > > >
>>> > > > > > > > >
>>> > > > > > > >
>>> > > > > > >
>>> > > > > >
>>> > > > >
>>> > > >
>>> > >
>>> >
>>> https://github.com/apache/incubator-apex-malhar/blob/devel-3/library/src/main/java/com/datatorrent/lib/db/jdbc/AbstractJdbcTransactionableOutputOperator.java
>>> > > > > > > > > >
>>> > > > > > > > > > They work with any kind PreparedStatement - insert or
>>> > update
>>> > > > > > > > > >
>>> > > > > > > > > > Chandni
>>> > > > > > > > > >
>>> > > > > > > > > >
>>> > > > > > > > > >
>>> > > > > > > > > > On Fri, Dec 11, 2015 at 10:59 AM, Bhupesh Chawda <
>>> > > > > > > > > bhupesh@datatorrent.com>
>>> > > > > > > > > > wrote:
>>> > > > > > > > > >
>>> > > > > > > > > >> Hi Chandni,
>>> > > > > > > > > >>
>>> > > > > > > > > >> I don't see an update query being handled in the
>>> operator.
>>> > > > Could
>>> > > > > > you
>>> > > > > > > > > >> please
>>> > > > > > > > > >> point me to the appropriate class?
>>> > > > > > > > > >> Or did you mean that handling a update query is just a
>>> > > matter
>>> > > > of
>>> > > > > > > > > extending
>>> > > > > > > > > >> the class and providing a concrete implementation?
>>> > > > > > > > > >>
>>> > > > > > > > > >> Thanks.
>>> > > > > > > > > >> -Bhupesh
>>> > > > > > > > > >>
>>> > > > > > > > > >> On Fri, Dec 11, 2015 at 10:42 PM, Chandni Singh <
>>> > > > > > > > > chandni@datatorrent.com>
>>> > > > > > > > > >> wrote:
>>> > > > > > > > > >>
>>> > > > > > > > > >> > Hi Bhupesh,
>>> > > > > > > > > >> >
>>> > > > > > > > > >> > The current abstract JDBC Output Operators in
>>> library
>>> > are
>>> > > > > > generic
>>> > > > > > > > and
>>> > > > > > > > > >> have
>>> > > > > > > > > >> > already been used in multiple POCs and
>>> applications. In
>>> > > fact
>>> > > > > > this
>>> > > > > > > > > >> operator
>>> > > > > > > > > >> > has matured through customer use cases. It is not
>>> just
>>> > an
>>> > > > > insert
>>> > > > > > > > > >> operator.
>>> > > > > > > > > >> > We have used it to perform update and inserts.
>>> > > > > > > > > >> >
>>> > > > > > > > > >> > That said, I don't think it is a good idea to
>>> introduce
>>> > > > input
>>> > > > > > > format
>>> > > > > > > > > in
>>> > > > > > > > > >> > these abstract implementations. It is written to
>>> handle
>>> > > any
>>> > > > > > type
>>> > > > > > > of
>>> > > > > > > > > >> query,
>>> > > > > > > > > >> > be it a procedure call (that was an actual customer
>>> use
>>> > > > case).
>>> > > > > > > > > >> >
>>> > > > > > > > > >> > Chandni
>>> > > > > > > > > >> >
>>> > > > > > > > > >> > On Fri, Dec 11, 2015 at 2:50 AM, Bhupesh Chawda <
>>> > > > > > > > > >> bhupesh@datatorrent.com>
>>> > > > > > > > > >> > wrote:
>>> > > > > > > > > >> >
>>> > > > > > > > > >> > > Hi All,
>>> > > > > > > > > >> > >
>>> > > > > > > > > >> > > We are planning to proceed with the following
>>> approach
>>> > > for
>>> > > > > > JDBC
>>> > > > > > > > > >> *update*
>>> > > > > > > > > >> > > operator:
>>> > > > > > > > > >> > >
>>> > > > > > > > > >> > > - *Update Query Configuration*
>>> > > > > > > > > >> > >
>>> > > > > > > > > >> > >
>>> > > > > > > > > >> > > - Example Update Query: *update tableName set
>>> a =
>>> > ?**
>>> > > > > > where b
>>> > > > > > > > = ?
>>> > > > > > > > > >> and
>>> > > > > > > > > >> > c
>>> > > > > > > > > >> > > > ?;*
>>> > > > > > > > > >> > > - Example JSON input array for parameter
>>> > > > instantiations:
>>> > > > > > > *[{a,
>>> > > > > > > > > >> > > expression, INTEGER}, {b, expression,
>>> VARCHAR}, {c,
>>> > > > > > > expression,
>>> > > > > > > > > >> > DATE}]*
>>> > > > > > > > > >> > >
>>> > > > > > > > > >> > > We are also planning to change the JDBC Output
>>> > Operator
>>> > > in
>>> > > > > > > Malhar
>>> > > > > > > > > >> Library
>>> > > > > > > > > >> > > which currently does just insert. We plan to make
>>> the
>>> > > > input
>>> > > > > > > format
>>> > > > > > > > > >> > > consistent for both insert and update and hence
>>> the
>>> > > change
>>> > > > > to
>>> > > > > > > the
>>> > > > > > > > > >> current
>>> > > > > > > > > >> > > way of configuration using JSON. Following would
>>> be
>>> > the
>>> > > > > config
>>> > > > > > > for
>>> > > > > > > > > >> > inserts:
>>> > > > > > > > > >> > >
>>> > > > > > > > > >> > > - *Insert Query Configuration*
>>> > > > > > > > > >> > >
>>> > > > > > > > > >> > >
>>> > > > > > > > > >> > > - Example Insert Query: *insert into tableName
>>> > values
>>> > > > (?,
>>> > > > > > ?,
>>> > > > > > > > .. ,
>>> > > > > > > > > >> ?);*
>>> > > > > > > > > >> > > - Example JSON input array for parameter
>>> > > > instantiations:
>>> > > > > > > *[{a,
>>> > > > > > > > > >> > > expression, INTEGER}, {b, expression,
>>> VARCHAR}, ..
>>> > ,
>>> > > > {c,
>>> > > > > > > > > >> expression,
>>> > > > > > > > > >> > > DATE}]*
>>> > > > > > > > > >> > >
>>> > > > > > > > > >> > > Please let us know your thoughts.
>>> > > > > > > > > >> > >
>>> > > > > > > > > >> > > Thanks.
>>> > > > > > > > > >> > >
>>> > > > > > > > > >> > > -Bhupesh
>>> > > > > > > > > >> > >
>>> > > > > > > > > >> > >
>>> > > > > > > > > >> > >
>>> > > > > > > > > >> > > On Wed, Dec 9, 2015 at 6:38 PM, Bhupesh Chawda <
>>> > > > > > > > > >> bhupesh@datatorrent.com>
>>> > > > > > > > > >> > > wrote:
>>> > > > > > > > > >> > >
>>> > > > > > > > > >> > > > Hi All,
>>> > > > > > > > > >> > > >
>>> > > > > > > > > >> > > > Would it be a good idea to introduce the update
>>> > > > > > functionality
>>> > > > > > > to
>>> > > > > > > > > the
>>> > > > > > > > > >> > JDBC
>>> > > > > > > > > >> > > > output operator in Apache Apex Malhar library.
>>> > > > > > > > > >> > > >
>>> > > > > > > > > >> > > > The following are possible approaches:
>>> > > > > > > > > >> > > >
>>> > > > > > > > > >> > > > 1. Accept a update query from the user with
>>> place
>>> > > > > holders
>>> > > > > > > for
>>> > > > > > > > > >> > values.
>>> > > > > > > > > >> > > > Example: *update tableName set a = ?, b = ?
>>> > where c
>>> > > > = ?
>>> > > > > > and
>>> > > > > > > > d >
>>> > > > > > > > > >> ?*.
>>> > > > > > > > > >> > > > Here "?" will be provided by the user as java
>>> > > > > expressions
>>> > > > > > > > which
>>> > > > > > > > > >> will
>>> > > > > > > > > >> > > be
>>> > > > > > > > > >> > > > evaluated from the incoming tuple.
>>> > > > > > > > > >> > > > 2. Another option is to accept in some
>>> > > configuration
>>> > > > > > format
>>> > > > > > > > > >> (json /
>>> > > > > > > > > >> > > > xml) the following and formulate the query
>>> in the
>>> > > > > > operator.
>>> > > > > > > > > This
>>> > > > > > > > > >> can
>>> > > > > > > > > >> > > become
>>> > > > > > > > > >> > > > arbitrarily complex.
>>> > > > > > > > > >> > > > 1. update clause columns
>>> > > > > > > > > >> > > > 2. update clause expressions
>>> > > > > > > > > >> > > > 3. where clause columns
>>> > > > > > > > > >> > > > 4. where clause expressions
>>> > > > > > > > > >> > > >
>>> > > > > > > > > >> > > > I am thinking about going ahead with 1. Please
>>> let
>>> > me
>>> > > > know
>>> > > > > > if
>>> > > > > > > > any
>>> > > > > > > > > >> other
>>> > > > > > > > > >> > > > option is possible and whether such a
>>> functionality
>>> > > > > already
>>> > > > > > > > exists
>>> > > > > > > > > >> in
>>> > > > > > > > > >> > > some
>>> > > > > > > > > >> > > > other class.
>>> > > > > > > > > >> > > >
>>> > > > > > > > > >> > > > Thanks.
>>> > > > > > > > > >> > > >
>>> > > > > > > > > >> > > > -Bhupesh
>>> > > > > > > > > >> > > >
>>> > > > > > > > > >> > >
>>> > > > > > > > > >> >
>>> > > > > > > > > >>
>>> > > > > > > > > >
>>> > > > > > > > > >
>>> > > > > > > > >
>>> > > > > > > >
>>> > > > > > >
>>> > > > > >
>>> > > > >
>>> > > >
>>> > >
>>> >
>>>
>>
>>
>
Re: Changes to JdbcOutputOperator
Posted by Bhupesh Chawda <bh...@datatorrent.com>.
Hi All,
In the pull request review, Sandeep pointed out that it would be good to
have an error port which can be used to redirect error tuples which cause
some SQL exception from the database.
Here is the design considered for implementing this:
- Add an error port to *AbstractTransactionableStoreOutputOperator*
- In *AbstractJdbcTransactionableOutputOperator*, when executing
*executeBatch*() for a prepared statement do the following:
- Catch the *BatchUpdateException*
- Identify whether the JDBC driver continued executing the batch in
spite of failures*, *or whether it stopped after the first failure.
Please see
https://docs.oracle.com/javase/7/docs/api/java/sql/BatchUpdateException.html
for more details. In each case, pick out the erroneous records
and redirect
them to the error port.
- In case the JDBC driver decided to stop after the first failure,
update the batch start index to skip the error record and resume
processing
other records in the batch.
I will add these changes as another commit in the same pull request.
Thanks.
~Bhupesh
On Thu, Mar 17, 2016 at 7:22 PM, Bhupesh Chawda <bh...@datatorrent.com>
wrote:
> Hi,
>
> I have made the changes as discussed in previous emails.
> Here is the pull request:
> https://github.com/apache/incubator-apex-malhar/pull/215
>
> Please help review the changes.
>
> Thanks
> ~Bhupesh
>
> On Tue, Mar 15, 2016 at 6:57 PM, Bhupesh Chawda <bh...@datatorrent.com>
> wrote:
>
>> Hi,
>>
>> Here are some of the details on what happens when automatic mapping is
>> done from POJO fields to DB columns ( i.e. when FieldInfo is not provided)
>>
>> - The reference list of columns is *all* the columns in the database
>> table.
>> - If the same field is found in POJO as in DB table, then we include
>> it in the columns to be inserted and create the corresponding getter from
>> POJO.
>> - If the same field is not found in the POJO, but the field is a
>> *nullable* field in the DB, then we drop it from the insert column
>> list. This means we essentially insert a *null* value for that field.
>> - If the same field is not found in the POJO and the field is a
>> *non-nullable* field in the DB, then we throw an exception.
>>
>> ~Bhupesh
>>
>> On Tue, Mar 15, 2016 at 2:57 PM, Bhupesh Chawda <bh...@datatorrent.com>
>> wrote:
>>
>>> Hi All,
>>>
>>> Here is the design I am considering for including the additional feature
>>> as mentioned in the previous email. Please note that this includes the
>>> previous feedback received on the design.
>>>
>>> 1. Rename JdbcPOJOOutputOperator -> *AbstractJdbcPOJOOutputOperator*
>>> 2. Add *JdbcPOJOInsertOutputOperator* extending from
>>> *AbstractJdbcPOJOOutputOperator*. This will be used for "*insert*"
>>> output query.
>>> 1. If FieldInfo (Mapping of POJO fields to DB columns) is
>>> provided by the user - then use only these columns to build the insert SQL
>>> string. Return this insert query as the update command.
>>> 2. If FieldInfo is not provided by the user - then assume a
>>> direct mapping between POJO fields and the DB columns. Extract list of
>>> columns from DB and populate all columns from POJO fields. The POJO fields
>>> will be assumed to be the same as DB column names.
>>> 3. Add *JdbcPOJONonInsertOutputOperator *extending from
>>> *AbstractJdbcPOJOOutputOperator*. This will be used for "*update /
>>> merge / delete*" output queries. [This design stays the same as
>>> discussed previously]
>>> 1. Accept a parametrized SQL string
>>> 2. Use the FieldInfo provided by the user to populate the
>>> parameters in the query.
>>> 3. Execute the query.
>>>
>>> Please provide your thoughts on this.
>>>
>>> Thanks.
>>> ~Bhupesh
>>>
>>>
>>> On Mon, Mar 14, 2016 at 6:29 PM, Priyanka Gugale <
>>> priyanka@datatorrent.com> wrote:
>>>
>>>> +1, this is simplifying operator configuration, we should do same for
>>>> other
>>>> DB operators as well.
>>>>
>>>> -Priyanka
>>>>
>>>> On Thu, Mar 10, 2016 at 5:34 PM, Bhupesh Chawda <
>>>> bhupesh@datatorrent.com>
>>>> wrote:
>>>>
>>>> > Hi All,
>>>> >
>>>> > Apart from extending the JDBC Output operator (for update, merge and
>>>> > delete), I am planning the following change to the "*insert*"
>>>> > functionality:
>>>> >
>>>> >
>>>> > - It was pointed out that - if the incoming POJO has fields which
>>>> are to
>>>> > be inserted into a database table, the user should not have to
>>>> specify
>>>> > any
>>>> > kind of mapping between POJO columns and database table column
>>>> names.
>>>> > This
>>>> > is possible if the POJO field names are same as the db column
>>>> names.
>>>> >
>>>> >
>>>> > - Here is what I am planning to do to address this:
>>>> > - Have a flag which indicates "*No mapping required. Assume
>>>> same POJO
>>>> > field names as the DB column names.*"
>>>> > - If this flag is true, extract DB column names (in addition to
>>>> the
>>>> > types, which is done currently) and create getters from POJO
>>>> based
>>>> > on the
>>>> > DB column types.
>>>> > - Use these getters to populate the parametrized "*insert*"
>>>> query.
>>>> >
>>>> >
>>>> > Note - Once this is done, the user would not have to specify any field
>>>> > descriptions. Just the DB table name would be sufficient. This would
>>>> only
>>>> > be possible if the DB column names are the same as the field names in
>>>> the
>>>> > POJO.
>>>> > Without this change, "*insert*" will be considered as just another DDL
>>>> > query like "update" / "delete" / "merge". We accept a parametrized
>>>> query
>>>> > and a mapping from the user for POJO field names to DB column names +
>>>> DB
>>>> > column types.
>>>> >
>>>> > Thanks.
>>>> > Bhupesh
>>>> >
>>>> >
>>>> > On Wed, Dec 30, 2015 at 12:56 PM, Bhupesh Chawda <
>>>> bhupesh@datatorrent.com>
>>>> > wrote:
>>>> >
>>>> > > Also, since we are not creating separate operators for insert and
>>>> > > update/merge, it seems we don't need an abstract class. We can
>>>> directly
>>>> > > modify JdbcPOJOOutputOperator.
>>>> > >
>>>> > > -Bhupesh
>>>> > >
>>>> > > On Wed, Dec 30, 2015 at 11:17 AM, Bhupesh Chawda <
>>>> > bhupesh@datatorrent.com>
>>>> > > wrote:
>>>> > >
>>>> > >> Also, a note regarding accepting fieldInfo objects:
>>>> > >>
>>>> > >> FieldInfo has fields for java type of the column, but not the SQL
>>>> data
>>>> > >> type which is needed to set the parameters in the SQL statement.
>>>> This
>>>> > still
>>>> > >> needs to be derived from the database (as in insert).
>>>> > >> In more complex scenarios, as mentioned earlier, this may not
>>>> always be
>>>> > >> possible. In this case we have the following options:
>>>> > >>
>>>> > >> 1. Accept the SQL data types from the user for the parameters
>>>> ("?")
>>>> > >> in a new data structure.
>>>> > >> 2. Accept the JSON structure as specified earlier.
>>>> > >> 3. Modify FieldInfo to have an additional optional field which
>>>> > >> indicates the SQL data type of the parameter ("?")
>>>> > >>
>>>> > >> I am planning to go ahead with option 3.
>>>> > >>
>>>> > >> Comments?
>>>> > >>
>>>> > >> -Bhupesh
>>>> > >>
>>>> > >>
>>>> > >>
>>>> > >> On Mon, Dec 28, 2015 at 11:26 PM, Chandni Singh <
>>>> > chandni@datatorrent.com>
>>>> > >> wrote:
>>>> > >>
>>>> > >>> Yeah that sounds good.
>>>> > >>>
>>>> > >>> Chandni
>>>> > >>>
>>>> > >>> On Mon, Dec 28, 2015 at 2:46 AM, Bhupesh Chawda <
>>>> > bhupesh@datatorrent.com
>>>> > >>> >
>>>> > >>> wrote:
>>>> > >>>
>>>> > >>> > Thanks Chandni for the comments.
>>>> > >>> >
>>>> > >>> > Additionally I think, we should do away with constructing the
>>>> SQL
>>>> > >>> query in
>>>> > >>> > the operator. This is because it is only possible in case of
>>>> simple
>>>> > >>> insert
>>>> > >>> > statements. In case a where clause is needed in the insert
>>>> statement,
>>>> > >>> we
>>>> > >>> > cannot construct the SQL easily. If we are accepting a
>>>> parametrized
>>>> > >>> query
>>>> > >>> > from the user for update/merge, why not do the same for insert
>>>> > >>> statements
>>>> > >>> > as well? Then the hierarchy would look like:
>>>> > >>> > - AbstractJdbcPOJOOutputOperator (As suggested)
>>>> > >>> > -- JdbcPOJOOutputOperator (Takes care of all statements insert,
>>>> > update,
>>>> > >>> > merge, delete)
>>>> > >>> >
>>>> > >>> > We don't need a separate operator for inserts and update/merge.
>>>> > >>> >
>>>> > >>> > Thanks.
>>>> > >>> > -Bhupesh
>>>> > >>> >
>>>> > >>> >
>>>> > >>> > On Mon, Dec 28, 2015 at 3:32 PM, Chandni Singh <
>>>> > >>> chandni@datatorrent.com>
>>>> > >>> > wrote:
>>>> > >>> >
>>>> > >>> > > 1. FieldInfo, is ultimately a custom object and any user
>>>> who uses
>>>> > >>> this
>>>> > >>> > > operator has to construct an object, populate it and then
>>>> use
>>>> > it.
>>>> > >>> We
>>>> > >>> > are
>>>> > >>> > > trying to avoid using any custom object and allow any user
>>>> to
>>>> > use
>>>> > >>> the
>>>> > >>> > > operator without writing any extra code; just
>>>> configuration.
>>>> > >>> > > FieldInfo is a way to provide configuration in a UI friendly
>>>> way.
>>>> > >>> > Providing
>>>> > >>> > > configuration as JSON is not UI friendly.
>>>> > >>> > >
>>>> > >>> > > 2. In case of update / merge, we need what SQL data types
>>>> that
>>>> > the
>>>> > >>> > > expression provided by the user would evaluate to. In case
>>>> of
>>>> > >>> insert
>>>> > >>> > we
>>>> > >>> > > can
>>>> > >>> > > go and fetch the data types of the columns directly from
>>>> DB.
>>>> > >>> However,
>>>> > >>> > > the
>>>> > >>> > > same is not possible for custom expressions; "avg(salary)"
>>>> for
>>>> > >>> > instance.
>>>> > >>> > > Ok so here is where you can make a change.
>>>> > >>> > > - JDBCPojoOutput can be renamed to
>>>> AbstractJDBCPojoOutpuOperator.
>>>> > >>> > > - Abstraction is to fetch the type of column.
>>>> > >>> > > - Add a concrete JDBCPojoInsertOutput that derives the types
>>>> of
>>>> > >>> columns
>>>> > >>> > > directly from DB. Please note that FieldInfo can also provide
>>>> type
>>>> > of
>>>> > >>> > > derived column.
>>>> > >>> > >
>>>> > >>> > >
>>>> > >>> > > You mentioned "We are trying to avoid using any custom object
>>>> and
>>>> > >>> allow
>>>> > >>> > any
>>>> > >>> > > user to use the
>>>> > >>> > > operator without writing any extra code".
>>>> > >>> > > This I think is specific to your use case. You can create an
>>>> > >>> extension of
>>>> > >>> > > the above which takes JSON blob and creates FieldInfos from
>>>> it.
>>>> > >>> > >
>>>> > >>> > > Chandni
>>>> > >>> > >
>>>> > >>> > >
>>>> > >>> > >
>>>> > >>> > >
>>>> > >>> > >
>>>> > >>> > > On Mon, Dec 28, 2015 at 1:48 AM, Bhupesh Chawda <
>>>> > >>> bhupesh@datatorrent.com
>>>> > >>> > >
>>>> > >>> > > wrote:
>>>> > >>> > >
>>>> > >>> > > > Hi Chandni,
>>>> > >>> > > >
>>>> > >>> > > > Following are the issues:
>>>> > >>> > > >
>>>> > >>> > > > 1. FieldInfo, is ultimately a custom object and any user
>>>> who
>>>> > >>> uses
>>>> > >>> > this
>>>> > >>> > > > operator has to construct an object, populate it and
>>>> then use
>>>> > >>> it. We
>>>> > >>> > > are
>>>> > >>> > > > trying to avoid using any custom object and allow any
>>>> user to
>>>> > >>> use
>>>> > >>> > the
>>>> > >>> > > > operator without writing any extra code; just
>>>> configuration.
>>>> > >>> > > > 2. In case of update / merge, we need what SQL data
>>>> types that
>>>> > >>> the
>>>> > >>> > > > expression provided by the user would evaluate to. In
>>>> case of
>>>> > >>> insert
>>>> > >>> > > we
>>>> > >>> > > > can
>>>> > >>> > > > go and fetch the data types of the columns directly from
>>>> DB.
>>>> > >>> > However,
>>>> > >>> > > > the
>>>> > >>> > > > same is not possible for custom expressions;
>>>> "avg(salary)" for
>>>> > >>> > > instance.
>>>> > >>> > > >
>>>> > >>> > > > Thanks.
>>>> > >>> > > >
>>>> > >>> > > > -Bhupesh
>>>> > >>> > > >
>>>> > >>> > > >
>>>> > >>> > > > On Mon, Dec 28, 2015 at 2:57 PM, Chandni Singh <
>>>> > >>> > chandni@datatorrent.com>
>>>> > >>> > > > wrote:
>>>> > >>> > > >
>>>> > >>> > > > > Hi Bhupesh,
>>>> > >>> > > > >
>>>> > >>> > > > > JDBCPojoOutputOperator was written for a demo and
>>>> therefore it
>>>> > >>> was
>>>> > >>> > > marked
>>>> > >>> > > > > Evolving which is why I had mentioned that you should
>>>> feel free
>>>> > >>> to
>>>> > >>> > > modify
>>>> > >>> > > > > it.
>>>> > >>> > > > >
>>>> > >>> > > > > I think an insert query can be as complex as any other
>>>> query.
>>>> > It
>>>> > >>> uses
>>>> > >>> > > > > FieldInfo because in the app builder it is easy for the
>>>> user to
>>>> > >>> > provide
>>>> > >>> > > > > that instead of JSON String.
>>>> > >>> > > > >
>>>> > >>> > > > > Can you please provide specifics about what it is that
>>>> you find
>>>> > >>> > > difficult
>>>> > >>> > > > > to change/implement for providing update/merge/delete
>>>> support
>>>> > in
>>>> > >>> > > > > JDBCPojoOutputOperator?
>>>> > >>> > > > >
>>>> > >>> > > > > Chandni
>>>> > >>> > > > >
>>>> > >>> > > > > On Mon, Dec 28, 2015 at 1:09 AM, Bhupesh Chawda <
>>>> > >>> > > bhupesh@datatorrent.com
>>>> > >>> > > > >
>>>> > >>> > > > > wrote:
>>>> > >>> > > > >
>>>> > >>> > > > > > Hi All,
>>>> > >>> > > > > >
>>>> > >>> > > > > > It has been pointed out that adding another class for
>>>> > handling
>>>> > >>> > > update /
>>>> > >>> > > > > > merge queries would not be a good option.
>>>> > >>> > > > > >
>>>> > >>> > > > > > Here are the current implementation details:
>>>> > >>> > > > > >
>>>> > >>> > > > > > - We have an existing class: JdbcPOJOOutputOperator
>>>> which
>>>> > >>> > accepts
>>>> > >>> > > a
>>>> > >>> > > > > list
>>>> > >>> > > > > > of FieldInfo objects. Each element of this list
>>>> indicates
>>>> > >>> the
>>>> > >>> > > > details
>>>> > >>> > > > > > (column name, pojo field expression and datatype) of
>>>> > fields
>>>> > >>> that
>>>> > >>> > > > need
>>>> > >>> > > > > > to be
>>>> > >>> > > > > > inserted. Using this, the operator formulates the
>>>> insert
>>>> > >>> query
>>>> > >>> > in
>>>> > >>> > > > the
>>>> > >>> > > > > > setup
>>>> > >>> > > > > > method and identifies the sql datatypes of these
>>>> columns
>>>> > >>> from
>>>> > >>> > the
>>>> > >>> > > > > > database
>>>> > >>> > > > > > using the table name.
>>>> > >>> > > > > >
>>>> > >>> > > > > >
>>>> > >>> > > > > > - Now, coming to the update / merge feature, it is
>>>> > >>> difficult to
>>>> > >>> > > > > > formulate the update / merge query in the operator
>>>> logic
>>>> > >>> due to
>>>> > >>> > > the
>>>> > >>> > > > > > complex
>>>> > >>> > > > > > structure of these statements. For this reason, we
>>>> plan to
>>>> > >>> take
>>>> > >>> > a
>>>> > >>> > > > > > parametrized SQL query from the user. This may look
>>>> like:
>>>> > >>> > *"update
>>>> > >>> > > > > table
>>>> > >>> > > > > > set x = ?, y = ? where z + w > ? and a == 1;"*. Such
>>>> > >>> statements
>>>> > >>> > > can
>>>> > >>> > > > be
>>>> > >>> > > > > > accepted from the user in addition to a json string
>>>> which
>>>> > >>> > > indicates
>>>> > >>> > > > > the
>>>> > >>> > > > > > details for the parameters: *column name, the pojo
>>>> > >>> expression
>>>> > >>> > and
>>>> > >>> > > > the
>>>> > >>> > > > > > sql data type* of the expression. Note that this
>>>> > >>> information is
>>>> > >>> > > > > similar
>>>> > >>> > > > > > to the FieldInfo object, but is a string which can be
>>>> > >>> configured
>>>> > >>> > > > > easily
>>>> > >>> > > > > > by
>>>> > >>> > > > > > the user. Also note that the data type which is
>>>> accepted
>>>> > is
>>>> > >>> the
>>>> > >>> > > SQL
>>>> > >>> > > > > data
>>>> > >>> > > > > > type. Using this info we can populate the
>>>> parametrized
>>>> > >>> query and
>>>> > >>> > > run
>>>> > >>> > > > > it
>>>> > >>> > > > > > based on the incoming POJO.
>>>> > >>> > > > > >
>>>> > >>> > > > > > The second approach is able to handle all kinds of
>>>> queries
>>>> > >>> (insert
>>>> > >>> > /
>>>> > >>> > > > > update
>>>> > >>> > > > > > / merge / delete). However, since we already have the
>>>> > >>> > > > > > JdbcPOJOOutputOperator, we would like to merge the new
>>>> > >>> > functionality
>>>> > >>> > > > into
>>>> > >>> > > > > > the same class.
>>>> > >>> > > > > >
>>>> > >>> > > > > > Here we have the following options:
>>>> > >>> > > > > >
>>>> > >>> > > > > > 1. Change the existing class
>>>> (JdbcPOJOOutputOperator) to
>>>> > the
>>>> > >>> > > second
>>>> > >>> > > > > > approach which is more generic and also handles
>>>> inserts.
>>>> > >>> > > > > > 2. Add the update/ merge functionality to the
>>>> existing
>>>> > class
>>>> > >>> > > without
>>>> > >>> > > > > > changing the existing functionality. This will have
>>>> two
>>>> > >>> > different
>>>> > >>> > > > ways
>>>> > >>> > > > > > that
>>>> > >>> > > > > > insert queries may be handled in the operator.
>>>> > >>> > > > > > 3. Add another class which extends from
>>>> > >>> JdbcPOJOOutputOperator
>>>> > >>> > and
>>>> > >>> > > > > have
>>>> > >>> > > > > > the update/merge functionality there. (This is not
>>>> > >>> recommended.)
>>>> > >>> > > > > > 4. Any other approach.
>>>> > >>> > > > > >
>>>> > >>> > > > > > Please suggest.
>>>> > >>> > > > > >
>>>> > >>> > > > > > Thanks.
>>>> > >>> > > > > >
>>>> > >>> > > > > > -Bhupesh.
>>>> > >>> > > > > >
>>>> > >>> > > > > >
>>>> > >>> > > > > > On Mon, Dec 14, 2015 at 11:04 AM, Chandni Singh <
>>>> > >>> > > > chandni@datatorrent.com
>>>> > >>> > > > > >
>>>> > >>> > > > > > wrote:
>>>> > >>> > > > > >
>>>> > >>> > > > > > > No I don't think we are restricting Malhar to just
>>>> abstract
>>>> > >>> > > classes.
>>>> > >>> > > > > > > Whenever they are couple of use cases that we see
>>>> quite
>>>> > >>> often, we
>>>> > >>> > > add
>>>> > >>> > > > > > > concrete implementations.
>>>> > >>> > > > > > >
>>>> > >>> > > > > > > For eg. FileLineInputOperator which is a concrete
>>>> > >>> implementation
>>>> > >>> > of
>>>> > >>> > > > > > > AbstractFileInputOperator. FSSliceReader is an
>>>> example as
>>>> > >>> well.
>>>> > >>> > > > > > >
>>>> > >>> > > > > > > In AbstractJdbcOutputOperator case there hasn't been
>>>> such
>>>> > >>> common
>>>> > >>> > > > > > > insert/update query.
>>>> > >>> > > > > > >
>>>> > >>> > > > > > > Also if you look at the example I provided, it is very
>>>> > >>> simple to
>>>> > >>> > > > > provide
>>>> > >>> > > > > > a
>>>> > >>> > > > > > > concrete implementation.
>>>> > >>> > > > > > >
>>>> > >>> > > > > > > If you would like to change JdbcPOJOOutputOperator to
>>>> work
>>>> > >>> for
>>>> > >>> > > > > > > "UPDATE/MERGE" then please go ahead.
>>>> > >>> > > > > > >
>>>> > >>> > > > > > > Chandni
>>>> > >>> > > > > > >
>>>> > >>> > > > > > > On Sun, Dec 13, 2015 at 8:47 PM, Bhupesh Chawda <
>>>> > >>> > > > > bhupesh@datatorrent.com
>>>> > >>> > > > > > >
>>>> > >>> > > > > > > wrote:
>>>> > >>> > > > > > >
>>>> > >>> > > > > > > > I see. So, just to understand more, do we plan to
>>>> keep
>>>> > >>> Malhar
>>>> > >>> > > > > > restricted
>>>> > >>> > > > > > > to
>>>> > >>> > > > > > > > the base functionality (as in abstract classes)?
>>>> And put
>>>> > >>> the
>>>> > >>> > > > > > > configuration
>>>> > >>> > > > > > > > aspect / concrete implementations in apps that use
>>>> these
>>>> > >>> > > operators?
>>>> > >>> > > > > > > >
>>>> > >>> > > > > > > > Thanks.
>>>> > >>> > > > > > > > Bhupesh
>>>> > >>> > > > > > > >
>>>> > >>> > > > > > > > On Sat, Dec 12, 2015 at 5:43 AM, Chandni Singh <
>>>> > >>> > > > > > chandni@datatorrent.com>
>>>> > >>> > > > > > > > wrote:
>>>> > >>> > > > > > > >
>>>> > >>> > > > > > > > > Hi,
>>>> > >>> > > > > > > > >
>>>> > >>> > > > > > > > > Here is an example of doing Upsert with JDBC:
>>>> > >>> > > > > > > > >
>>>> > >>> > > > > > > > >
>>>> > >>> > > > > > > >
>>>> > >>> > > > > > >
>>>> > >>> > > > > >
>>>> > >>> > > > >
>>>> > >>> > > >
>>>> > >>> > >
>>>> > >>> >
>>>> > >>>
>>>> >
>>>> https://github.com/chandnisingh/Malhar/blob/examples/apps/jdbc/src/main/java/com/datatorrent/jdbc/JdbcWriter.java
>>>> > >>> > > > > > > > >
>>>> > >>> > > > > > > > > Thanks,
>>>> > >>> > > > > > > > > Chandni
>>>> > >>> > > > > > > > >
>>>> > >>> > > > > > > > > On Fri, Dec 11, 2015 at 11:19 AM, Chandni Singh <
>>>> > >>> > > > > > > chandni@datatorrent.com
>>>> > >>> > > > > > > > >
>>>> > >>> > > > > > > > > wrote:
>>>> > >>> > > > > > > > >
>>>> > >>> > > > > > > > > > The operators are under Malhar/lib/db/jdbc.
>>>> > >>> > > > > > > > > >
>>>> > >>> > > > > > > > > > Here is one of them:
>>>> > >>> > > > > > > > > >
>>>> > >>> > > > > > > > > >
>>>> > >>> > > > > > > > >
>>>> > >>> > > > > > > >
>>>> > >>> > > > > > >
>>>> > >>> > > > > >
>>>> > >>> > > > >
>>>> > >>> > > >
>>>> > >>> > >
>>>> > >>> >
>>>> > >>>
>>>> >
>>>> https://github.com/apache/incubator-apex-malhar/blob/devel-3/library/src/main/java/com/datatorrent/lib/db/jdbc/AbstractJdbcTransactionableOutputOperator.java
>>>> > >>> > > > > > > > > >
>>>> > >>> > > > > > > > > > They work with any kind PreparedStatement -
>>>> insert or
>>>> > >>> > update
>>>> > >>> > > > > > > > > >
>>>> > >>> > > > > > > > > > Chandni
>>>> > >>> > > > > > > > > >
>>>> > >>> > > > > > > > > >
>>>> > >>> > > > > > > > > >
>>>> > >>> > > > > > > > > > On Fri, Dec 11, 2015 at 10:59 AM, Bhupesh
>>>> Chawda <
>>>> > >>> > > > > > > > > bhupesh@datatorrent.com>
>>>> > >>> > > > > > > > > > wrote:
>>>> > >>> > > > > > > > > >
>>>> > >>> > > > > > > > > >> Hi Chandni,
>>>> > >>> > > > > > > > > >>
>>>> > >>> > > > > > > > > >> I don't see an update query being handled in
>>>> the
>>>> > >>> operator.
>>>> > >>> > > > Could
>>>> > >>> > > > > > you
>>>> > >>> > > > > > > > > >> please
>>>> > >>> > > > > > > > > >> point me to the appropriate class?
>>>> > >>> > > > > > > > > >> Or did you mean that handling a update query is
>>>> > just a
>>>> > >>> > > matter
>>>> > >>> > > > of
>>>> > >>> > > > > > > > > extending
>>>> > >>> > > > > > > > > >> the class and providing a concrete
>>>> implementation?
>>>> > >>> > > > > > > > > >>
>>>> > >>> > > > > > > > > >> Thanks.
>>>> > >>> > > > > > > > > >> -Bhupesh
>>>> > >>> > > > > > > > > >>
>>>> > >>> > > > > > > > > >> On Fri, Dec 11, 2015 at 10:42 PM, Chandni
>>>> Singh <
>>>> > >>> > > > > > > > > chandni@datatorrent.com>
>>>> > >>> > > > > > > > > >> wrote:
>>>> > >>> > > > > > > > > >>
>>>> > >>> > > > > > > > > >> > Hi Bhupesh,
>>>> > >>> > > > > > > > > >> >
>>>> > >>> > > > > > > > > >> > The current abstract JDBC Output Operators
>>>> in
>>>> > >>> library
>>>> > >>> > are
>>>> > >>> > > > > > generic
>>>> > >>> > > > > > > > and
>>>> > >>> > > > > > > > > >> have
>>>> > >>> > > > > > > > > >> > already been used in multiple POCs and
>>>> > >>> applications. In
>>>> > >>> > > fact
>>>> > >>> > > > > > this
>>>> > >>> > > > > > > > > >> operator
>>>> > >>> > > > > > > > > >> > has matured through customer use cases. It
>>>> is not
>>>> > >>> just
>>>> > >>> > an
>>>> > >>> > > > > insert
>>>> > >>> > > > > > > > > >> operator.
>>>> > >>> > > > > > > > > >> > We have used it to perform update and
>>>> inserts.
>>>> > >>> > > > > > > > > >> >
>>>> > >>> > > > > > > > > >> > That said, I don't think it is a good idea to
>>>> > >>> introduce
>>>> > >>> > > > input
>>>> > >>> > > > > > > format
>>>> > >>> > > > > > > > > in
>>>> > >>> > > > > > > > > >> > these abstract implementations. It is
>>>> written to
>>>> > >>> handle
>>>> > >>> > > any
>>>> > >>> > > > > > type
>>>> > >>> > > > > > > of
>>>> > >>> > > > > > > > > >> query,
>>>> > >>> > > > > > > > > >> > be it a procedure call (that was an actual
>>>> > customer
>>>> > >>> use
>>>> > >>> > > > case).
>>>> > >>> > > > > > > > > >> >
>>>> > >>> > > > > > > > > >> > Chandni
>>>> > >>> > > > > > > > > >> >
>>>> > >>> > > > > > > > > >> > On Fri, Dec 11, 2015 at 2:50 AM, Bhupesh
>>>> Chawda <
>>>> > >>> > > > > > > > > >> bhupesh@datatorrent.com>
>>>> > >>> > > > > > > > > >> > wrote:
>>>> > >>> > > > > > > > > >> >
>>>> > >>> > > > > > > > > >> > > Hi All,
>>>> > >>> > > > > > > > > >> > >
>>>> > >>> > > > > > > > > >> > > We are planning to proceed with the
>>>> following
>>>> > >>> approach
>>>> > >>> > > for
>>>> > >>> > > > > > JDBC
>>>> > >>> > > > > > > > > >> *update*
>>>> > >>> > > > > > > > > >> > > operator:
>>>> > >>> > > > > > > > > >> > >
>>>> > >>> > > > > > > > > >> > > - *Update Query Configuration*
>>>> > >>> > > > > > > > > >> > >
>>>> > >>> > > > > > > > > >> > >
>>>> > >>> > > > > > > > > >> > > - Example Update Query: *update
>>>> tableName set
>>>> > >>> a =
>>>> > >>> > ?**
>>>> > >>> > > > > > where b
>>>> > >>> > > > > > > > = ?
>>>> > >>> > > > > > > > > >> and
>>>> > >>> > > > > > > > > >> > c
>>>> > >>> > > > > > > > > >> > > > ?;*
>>>> > >>> > > > > > > > > >> > > - Example JSON input array for parameter
>>>> > >>> > > > instantiations:
>>>> > >>> > > > > > > *[{a,
>>>> > >>> > > > > > > > > >> > > expression, INTEGER}, {b, expression,
>>>> > >>> VARCHAR}, {c,
>>>> > >>> > > > > > > expression,
>>>> > >>> > > > > > > > > >> > DATE}]*
>>>> > >>> > > > > > > > > >> > >
>>>> > >>> > > > > > > > > >> > > We are also planning to change the JDBC
>>>> Output
>>>> > >>> > Operator
>>>> > >>> > > in
>>>> > >>> > > > > > > Malhar
>>>> > >>> > > > > > > > > >> Library
>>>> > >>> > > > > > > > > >> > > which currently does just insert. We plan
>>>> to
>>>> > make
>>>> > >>> the
>>>> > >>> > > > input
>>>> > >>> > > > > > > format
>>>> > >>> > > > > > > > > >> > > consistent for both insert and update and
>>>> hence
>>>> > >>> the
>>>> > >>> > > change
>>>> > >>> > > > > to
>>>> > >>> > > > > > > the
>>>> > >>> > > > > > > > > >> current
>>>> > >>> > > > > > > > > >> > > way of configuration using JSON. Following
>>>> would
>>>> > >>> be
>>>> > >>> > the
>>>> > >>> > > > > config
>>>> > >>> > > > > > > for
>>>> > >>> > > > > > > > > >> > inserts:
>>>> > >>> > > > > > > > > >> > >
>>>> > >>> > > > > > > > > >> > > - *Insert Query Configuration*
>>>> > >>> > > > > > > > > >> > >
>>>> > >>> > > > > > > > > >> > >
>>>> > >>> > > > > > > > > >> > > - Example Insert Query: *insert into
>>>> > tableName
>>>> > >>> > values
>>>> > >>> > > > (?,
>>>> > >>> > > > > > ?,
>>>> > >>> > > > > > > > .. ,
>>>> > >>> > > > > > > > > >> ?);*
>>>> > >>> > > > > > > > > >> > > - Example JSON input array for parameter
>>>> > >>> > > > instantiations:
>>>> > >>> > > > > > > *[{a,
>>>> > >>> > > > > > > > > >> > > expression, INTEGER}, {b, expression,
>>>> > >>> VARCHAR}, ..
>>>> > >>> > ,
>>>> > >>> > > > {c,
>>>> > >>> > > > > > > > > >> expression,
>>>> > >>> > > > > > > > > >> > > DATE}]*
>>>> > >>> > > > > > > > > >> > >
>>>> > >>> > > > > > > > > >> > > Please let us know your thoughts.
>>>> > >>> > > > > > > > > >> > >
>>>> > >>> > > > > > > > > >> > > Thanks.
>>>> > >>> > > > > > > > > >> > >
>>>> > >>> > > > > > > > > >> > > -Bhupesh
>>>> > >>> > > > > > > > > >> > >
>>>> > >>> > > > > > > > > >> > >
>>>> > >>> > > > > > > > > >> > >
>>>> > >>> > > > > > > > > >> > > On Wed, Dec 9, 2015 at 6:38 PM, Bhupesh
>>>> Chawda <
>>>> > >>> > > > > > > > > >> bhupesh@datatorrent.com>
>>>> > >>> > > > > > > > > >> > > wrote:
>>>> > >>> > > > > > > > > >> > >
>>>> > >>> > > > > > > > > >> > > > Hi All,
>>>> > >>> > > > > > > > > >> > > >
>>>> > >>> > > > > > > > > >> > > > Would it be a good idea to introduce the
>>>> > update
>>>> > >>> > > > > > functionality
>>>> > >>> > > > > > > to
>>>> > >>> > > > > > > > > the
>>>> > >>> > > > > > > > > >> > JDBC
>>>> > >>> > > > > > > > > >> > > > output operator in Apache Apex Malhar
>>>> library.
>>>> > >>> > > > > > > > > >> > > >
>>>> > >>> > > > > > > > > >> > > > The following are possible approaches:
>>>> > >>> > > > > > > > > >> > > >
>>>> > >>> > > > > > > > > >> > > > 1. Accept a update query from the
>>>> user with
>>>> > >>> place
>>>> > >>> > > > > holders
>>>> > >>> > > > > > > for
>>>> > >>> > > > > > > > > >> > values.
>>>> > >>> > > > > > > > > >> > > > Example: *update tableName set a = ?,
>>>> b = ?
>>>> > >>> > where c
>>>> > >>> > > > = ?
>>>> > >>> > > > > > and
>>>> > >>> > > > > > > > d >
>>>> > >>> > > > > > > > > >> ?*.
>>>> > >>> > > > > > > > > >> > > > Here "?" will be provided by the user
>>>> as
>>>> > java
>>>> > >>> > > > > expressions
>>>> > >>> > > > > > > > which
>>>> > >>> > > > > > > > > >> will
>>>> > >>> > > > > > > > > >> > > be
>>>> > >>> > > > > > > > > >> > > > evaluated from the incoming tuple.
>>>> > >>> > > > > > > > > >> > > > 2. Another option is to accept in some
>>>> > >>> > > configuration
>>>> > >>> > > > > > format
>>>> > >>> > > > > > > > > >> (json /
>>>> > >>> > > > > > > > > >> > > > xml) the following and formulate the
>>>> query
>>>> > >>> in the
>>>> > >>> > > > > > operator.
>>>> > >>> > > > > > > > > This
>>>> > >>> > > > > > > > > >> can
>>>> > >>> > > > > > > > > >> > > become
>>>> > >>> > > > > > > > > >> > > > arbitrarily complex.
>>>> > >>> > > > > > > > > >> > > > 1. update clause columns
>>>> > >>> > > > > > > > > >> > > > 2. update clause expressions
>>>> > >>> > > > > > > > > >> > > > 3. where clause columns
>>>> > >>> > > > > > > > > >> > > > 4. where clause expressions
>>>> > >>> > > > > > > > > >> > > >
>>>> > >>> > > > > > > > > >> > > > I am thinking about going ahead with 1.
>>>> Please
>>>> > >>> let
>>>> > >>> > me
>>>> > >>> > > > know
>>>> > >>> > > > > > if
>>>> > >>> > > > > > > > any
>>>> > >>> > > > > > > > > >> other
>>>> > >>> > > > > > > > > >> > > > option is possible and whether such a
>>>> > >>> functionality
>>>> > >>> > > > > already
>>>> > >>> > > > > > > > exists
>>>> > >>> > > > > > > > > >> in
>>>> > >>> > > > > > > > > >> > > some
>>>> > >>> > > > > > > > > >> > > > other class.
>>>> > >>> > > > > > > > > >> > > >
>>>> > >>> > > > > > > > > >> > > > Thanks.
>>>> > >>> > > > > > > > > >> > > >
>>>> > >>> > > > > > > > > >> > > > -Bhupesh
>>>> > >>> > > > > > > > > >> > > >
>>>> > >>> > > > > > > > > >> > >
>>>> > >>> > > > > > > > > >> >
>>>> > >>> > > > > > > > > >>
>>>> > >>> > > > > > > > > >
>>>> > >>> > > > > > > > > >
>>>> > >>> > > > > > > > >
>>>> > >>> > > > > > > >
>>>> > >>> > > > > > >
>>>> > >>> > > > > >
>>>> > >>> > > > >
>>>> > >>> > > >
>>>> > >>> > >
>>>> > >>> >
>>>> > >>>
>>>> > >>
>>>> > >>
>>>> > >
>>>> >
>>>>
>>>
>>>
>>
>
Re: Changes to JdbcOutputOperator
Posted by Bhupesh Chawda <bh...@datatorrent.com>.
Hi,
I have made the changes as discussed in previous emails.
Here is the pull request:
https://github.com/apache/incubator-apex-malhar/pull/215
Please help review the changes.
Thanks
~Bhupesh
On Tue, Mar 15, 2016 at 6:57 PM, Bhupesh Chawda <bh...@datatorrent.com>
wrote:
> Hi,
>
> Here are some of the details on what happens when automatic mapping is
> done from POJO fields to DB columns ( i.e. when FieldInfo is not provided)
>
> - The reference list of columns is *all* the columns in the database
> table.
> - If the same field is found in POJO as in DB table, then we include
> it in the columns to be inserted and create the corresponding getter from
> POJO.
> - If the same field is not found in the POJO, but the field is a
> *nullable* field in the DB, then we drop it from the insert column
> list. This means we essentially insert a *null* value for that field.
> - If the same field is not found in the POJO and the field is a
> *non-nullable* field in the DB, then we throw an exception.
>
> ~Bhupesh
>
> On Tue, Mar 15, 2016 at 2:57 PM, Bhupesh Chawda <bh...@datatorrent.com>
> wrote:
>
>> Hi All,
>>
>> Here is the design I am considering for including the additional feature
>> as mentioned in the previous email. Please note that this includes the
>> previous feedback received on the design.
>>
>> 1. Rename JdbcPOJOOutputOperator -> *AbstractJdbcPOJOOutputOperator*
>> 2. Add *JdbcPOJOInsertOutputOperator* extending from
>> *AbstractJdbcPOJOOutputOperator*. This will be used for "*insert*"
>> output query.
>> 1. If FieldInfo (Mapping of POJO fields to DB columns) is provided
>> by the user - then use only these columns to build the insert SQL string.
>> Return this insert query as the update command.
>> 2. If FieldInfo is not provided by the user - then assume a direct
>> mapping between POJO fields and the DB columns. Extract list of columns
>> from DB and populate all columns from POJO fields. The POJO fields will be
>> assumed to be the same as DB column names.
>> 3. Add *JdbcPOJONonInsertOutputOperator *extending from
>> *AbstractJdbcPOJOOutputOperator*. This will be used for "*update /
>> merge / delete*" output queries. [This design stays the same as
>> discussed previously]
>> 1. Accept a parametrized SQL string
>> 2. Use the FieldInfo provided by the user to populate the
>> parameters in the query.
>> 3. Execute the query.
>>
>> Please provide your thoughts on this.
>>
>> Thanks.
>> ~Bhupesh
>>
>>
>> On Mon, Mar 14, 2016 at 6:29 PM, Priyanka Gugale <
>> priyanka@datatorrent.com> wrote:
>>
>>> +1, this is simplifying operator configuration, we should do same for
>>> other
>>> DB operators as well.
>>>
>>> -Priyanka
>>>
>>> On Thu, Mar 10, 2016 at 5:34 PM, Bhupesh Chawda <bhupesh@datatorrent.com
>>> >
>>> wrote:
>>>
>>> > Hi All,
>>> >
>>> > Apart from extending the JDBC Output operator (for update, merge and
>>> > delete), I am planning the following change to the "*insert*"
>>> > functionality:
>>> >
>>> >
>>> > - It was pointed out that - if the incoming POJO has fields which
>>> are to
>>> > be inserted into a database table, the user should not have to
>>> specify
>>> > any
>>> > kind of mapping between POJO columns and database table column
>>> names.
>>> > This
>>> > is possible if the POJO field names are same as the db column names.
>>> >
>>> >
>>> > - Here is what I am planning to do to address this:
>>> > - Have a flag which indicates "*No mapping required. Assume same
>>> POJO
>>> > field names as the DB column names.*"
>>> > - If this flag is true, extract DB column names (in addition to
>>> the
>>> > types, which is done currently) and create getters from POJO
>>> based
>>> > on the
>>> > DB column types.
>>> > - Use these getters to populate the parametrized "*insert*"
>>> query.
>>> >
>>> >
>>> > Note - Once this is done, the user would not have to specify any field
>>> > descriptions. Just the DB table name would be sufficient. This would
>>> only
>>> > be possible if the DB column names are the same as the field names in
>>> the
>>> > POJO.
>>> > Without this change, "*insert*" will be considered as just another DDL
>>> > query like "update" / "delete" / "merge". We accept a parametrized
>>> query
>>> > and a mapping from the user for POJO field names to DB column names +
>>> DB
>>> > column types.
>>> >
>>> > Thanks.
>>> > Bhupesh
>>> >
>>> >
>>> > On Wed, Dec 30, 2015 at 12:56 PM, Bhupesh Chawda <
>>> bhupesh@datatorrent.com>
>>> > wrote:
>>> >
>>> > > Also, since we are not creating separate operators for insert and
>>> > > update/merge, it seems we don't need an abstract class. We can
>>> directly
>>> > > modify JdbcPOJOOutputOperator.
>>> > >
>>> > > -Bhupesh
>>> > >
>>> > > On Wed, Dec 30, 2015 at 11:17 AM, Bhupesh Chawda <
>>> > bhupesh@datatorrent.com>
>>> > > wrote:
>>> > >
>>> > >> Also, a note regarding accepting fieldInfo objects:
>>> > >>
>>> > >> FieldInfo has fields for java type of the column, but not the SQL
>>> data
>>> > >> type which is needed to set the parameters in the SQL statement.
>>> This
>>> > still
>>> > >> needs to be derived from the database (as in insert).
>>> > >> In more complex scenarios, as mentioned earlier, this may not
>>> always be
>>> > >> possible. In this case we have the following options:
>>> > >>
>>> > >> 1. Accept the SQL data types from the user for the parameters
>>> ("?")
>>> > >> in a new data structure.
>>> > >> 2. Accept the JSON structure as specified earlier.
>>> > >> 3. Modify FieldInfo to have an additional optional field which
>>> > >> indicates the SQL data type of the parameter ("?")
>>> > >>
>>> > >> I am planning to go ahead with option 3.
>>> > >>
>>> > >> Comments?
>>> > >>
>>> > >> -Bhupesh
>>> > >>
>>> > >>
>>> > >>
>>> > >> On Mon, Dec 28, 2015 at 11:26 PM, Chandni Singh <
>>> > chandni@datatorrent.com>
>>> > >> wrote:
>>> > >>
>>> > >>> Yeah that sounds good.
>>> > >>>
>>> > >>> Chandni
>>> > >>>
>>> > >>> On Mon, Dec 28, 2015 at 2:46 AM, Bhupesh Chawda <
>>> > bhupesh@datatorrent.com
>>> > >>> >
>>> > >>> wrote:
>>> > >>>
>>> > >>> > Thanks Chandni for the comments.
>>> > >>> >
>>> > >>> > Additionally I think, we should do away with constructing the SQL
>>> > >>> query in
>>> > >>> > the operator. This is because it is only possible in case of
>>> simple
>>> > >>> insert
>>> > >>> > statements. In case a where clause is needed in the insert
>>> statement,
>>> > >>> we
>>> > >>> > cannot construct the SQL easily. If we are accepting a
>>> parametrized
>>> > >>> query
>>> > >>> > from the user for update/merge, why not do the same for insert
>>> > >>> statements
>>> > >>> > as well? Then the hierarchy would look like:
>>> > >>> > - AbstractJdbcPOJOOutputOperator (As suggested)
>>> > >>> > -- JdbcPOJOOutputOperator (Takes care of all statements insert,
>>> > update,
>>> > >>> > merge, delete)
>>> > >>> >
>>> > >>> > We don't need a separate operator for inserts and update/merge.
>>> > >>> >
>>> > >>> > Thanks.
>>> > >>> > -Bhupesh
>>> > >>> >
>>> > >>> >
>>> > >>> > On Mon, Dec 28, 2015 at 3:32 PM, Chandni Singh <
>>> > >>> chandni@datatorrent.com>
>>> > >>> > wrote:
>>> > >>> >
>>> > >>> > > 1. FieldInfo, is ultimately a custom object and any user who
>>> uses
>>> > >>> this
>>> > >>> > > operator has to construct an object, populate it and then
>>> use
>>> > it.
>>> > >>> We
>>> > >>> > are
>>> > >>> > > trying to avoid using any custom object and allow any user
>>> to
>>> > use
>>> > >>> the
>>> > >>> > > operator without writing any extra code; just configuration.
>>> > >>> > > FieldInfo is a way to provide configuration in a UI friendly
>>> way.
>>> > >>> > Providing
>>> > >>> > > configuration as JSON is not UI friendly.
>>> > >>> > >
>>> > >>> > > 2. In case of update / merge, we need what SQL data types
>>> that
>>> > the
>>> > >>> > > expression provided by the user would evaluate to. In case
>>> of
>>> > >>> insert
>>> > >>> > we
>>> > >>> > > can
>>> > >>> > > go and fetch the data types of the columns directly from DB.
>>> > >>> However,
>>> > >>> > > the
>>> > >>> > > same is not possible for custom expressions; "avg(salary)"
>>> for
>>> > >>> > instance.
>>> > >>> > > Ok so here is where you can make a change.
>>> > >>> > > - JDBCPojoOutput can be renamed to
>>> AbstractJDBCPojoOutpuOperator.
>>> > >>> > > - Abstraction is to fetch the type of column.
>>> > >>> > > - Add a concrete JDBCPojoInsertOutput that derives the types
>>> of
>>> > >>> columns
>>> > >>> > > directly from DB. Please note that FieldInfo can also provide
>>> type
>>> > of
>>> > >>> > > derived column.
>>> > >>> > >
>>> > >>> > >
>>> > >>> > > You mentioned "We are trying to avoid using any custom object
>>> and
>>> > >>> allow
>>> > >>> > any
>>> > >>> > > user to use the
>>> > >>> > > operator without writing any extra code".
>>> > >>> > > This I think is specific to your use case. You can create an
>>> > >>> extension of
>>> > >>> > > the above which takes JSON blob and creates FieldInfos from it.
>>> > >>> > >
>>> > >>> > > Chandni
>>> > >>> > >
>>> > >>> > >
>>> > >>> > >
>>> > >>> > >
>>> > >>> > >
>>> > >>> > > On Mon, Dec 28, 2015 at 1:48 AM, Bhupesh Chawda <
>>> > >>> bhupesh@datatorrent.com
>>> > >>> > >
>>> > >>> > > wrote:
>>> > >>> > >
>>> > >>> > > > Hi Chandni,
>>> > >>> > > >
>>> > >>> > > > Following are the issues:
>>> > >>> > > >
>>> > >>> > > > 1. FieldInfo, is ultimately a custom object and any user
>>> who
>>> > >>> uses
>>> > >>> > this
>>> > >>> > > > operator has to construct an object, populate it and then
>>> use
>>> > >>> it. We
>>> > >>> > > are
>>> > >>> > > > trying to avoid using any custom object and allow any
>>> user to
>>> > >>> use
>>> > >>> > the
>>> > >>> > > > operator without writing any extra code; just
>>> configuration.
>>> > >>> > > > 2. In case of update / merge, we need what SQL data types
>>> that
>>> > >>> the
>>> > >>> > > > expression provided by the user would evaluate to. In
>>> case of
>>> > >>> insert
>>> > >>> > > we
>>> > >>> > > > can
>>> > >>> > > > go and fetch the data types of the columns directly from
>>> DB.
>>> > >>> > However,
>>> > >>> > > > the
>>> > >>> > > > same is not possible for custom expressions;
>>> "avg(salary)" for
>>> > >>> > > instance.
>>> > >>> > > >
>>> > >>> > > > Thanks.
>>> > >>> > > >
>>> > >>> > > > -Bhupesh
>>> > >>> > > >
>>> > >>> > > >
>>> > >>> > > > On Mon, Dec 28, 2015 at 2:57 PM, Chandni Singh <
>>> > >>> > chandni@datatorrent.com>
>>> > >>> > > > wrote:
>>> > >>> > > >
>>> > >>> > > > > Hi Bhupesh,
>>> > >>> > > > >
>>> > >>> > > > > JDBCPojoOutputOperator was written for a demo and
>>> therefore it
>>> > >>> was
>>> > >>> > > marked
>>> > >>> > > > > Evolving which is why I had mentioned that you should feel
>>> free
>>> > >>> to
>>> > >>> > > modify
>>> > >>> > > > > it.
>>> > >>> > > > >
>>> > >>> > > > > I think an insert query can be as complex as any other
>>> query.
>>> > It
>>> > >>> uses
>>> > >>> > > > > FieldInfo because in the app builder it is easy for the
>>> user to
>>> > >>> > provide
>>> > >>> > > > > that instead of JSON String.
>>> > >>> > > > >
>>> > >>> > > > > Can you please provide specifics about what it is that you
>>> find
>>> > >>> > > difficult
>>> > >>> > > > > to change/implement for providing update/merge/delete
>>> support
>>> > in
>>> > >>> > > > > JDBCPojoOutputOperator?
>>> > >>> > > > >
>>> > >>> > > > > Chandni
>>> > >>> > > > >
>>> > >>> > > > > On Mon, Dec 28, 2015 at 1:09 AM, Bhupesh Chawda <
>>> > >>> > > bhupesh@datatorrent.com
>>> > >>> > > > >
>>> > >>> > > > > wrote:
>>> > >>> > > > >
>>> > >>> > > > > > Hi All,
>>> > >>> > > > > >
>>> > >>> > > > > > It has been pointed out that adding another class for
>>> > handling
>>> > >>> > > update /
>>> > >>> > > > > > merge queries would not be a good option.
>>> > >>> > > > > >
>>> > >>> > > > > > Here are the current implementation details:
>>> > >>> > > > > >
>>> > >>> > > > > > - We have an existing class: JdbcPOJOOutputOperator
>>> which
>>> > >>> > accepts
>>> > >>> > > a
>>> > >>> > > > > list
>>> > >>> > > > > > of FieldInfo objects. Each element of this list
>>> indicates
>>> > >>> the
>>> > >>> > > > details
>>> > >>> > > > > > (column name, pojo field expression and datatype) of
>>> > fields
>>> > >>> that
>>> > >>> > > > need
>>> > >>> > > > > > to be
>>> > >>> > > > > > inserted. Using this, the operator formulates the
>>> insert
>>> > >>> query
>>> > >>> > in
>>> > >>> > > > the
>>> > >>> > > > > > setup
>>> > >>> > > > > > method and identifies the sql datatypes of these
>>> columns
>>> > >>> from
>>> > >>> > the
>>> > >>> > > > > > database
>>> > >>> > > > > > using the table name.
>>> > >>> > > > > >
>>> > >>> > > > > >
>>> > >>> > > > > > - Now, coming to the update / merge feature, it is
>>> > >>> difficult to
>>> > >>> > > > > > formulate the update / merge query in the operator
>>> logic
>>> > >>> due to
>>> > >>> > > the
>>> > >>> > > > > > complex
>>> > >>> > > > > > structure of these statements. For this reason, we
>>> plan to
>>> > >>> take
>>> > >>> > a
>>> > >>> > > > > > parametrized SQL query from the user. This may look
>>> like:
>>> > >>> > *"update
>>> > >>> > > > > table
>>> > >>> > > > > > set x = ?, y = ? where z + w > ? and a == 1;"*. Such
>>> > >>> statements
>>> > >>> > > can
>>> > >>> > > > be
>>> > >>> > > > > > accepted from the user in addition to a json string
>>> which
>>> > >>> > > indicates
>>> > >>> > > > > the
>>> > >>> > > > > > details for the parameters: *column name, the pojo
>>> > >>> expression
>>> > >>> > and
>>> > >>> > > > the
>>> > >>> > > > > > sql data type* of the expression. Note that this
>>> > >>> information is
>>> > >>> > > > > similar
>>> > >>> > > > > > to the FieldInfo object, but is a string which can be
>>> > >>> configured
>>> > >>> > > > > easily
>>> > >>> > > > > > by
>>> > >>> > > > > > the user. Also note that the data type which is
>>> accepted
>>> > is
>>> > >>> the
>>> > >>> > > SQL
>>> > >>> > > > > data
>>> > >>> > > > > > type. Using this info we can populate the parametrized
>>> > >>> query and
>>> > >>> > > run
>>> > >>> > > > > it
>>> > >>> > > > > > based on the incoming POJO.
>>> > >>> > > > > >
>>> > >>> > > > > > The second approach is able to handle all kinds of
>>> queries
>>> > >>> (insert
>>> > >>> > /
>>> > >>> > > > > update
>>> > >>> > > > > > / merge / delete). However, since we already have the
>>> > >>> > > > > > JdbcPOJOOutputOperator, we would like to merge the new
>>> > >>> > functionality
>>> > >>> > > > into
>>> > >>> > > > > > the same class.
>>> > >>> > > > > >
>>> > >>> > > > > > Here we have the following options:
>>> > >>> > > > > >
>>> > >>> > > > > > 1. Change the existing class (JdbcPOJOOutputOperator)
>>> to
>>> > the
>>> > >>> > > second
>>> > >>> > > > > > approach which is more generic and also handles
>>> inserts.
>>> > >>> > > > > > 2. Add the update/ merge functionality to the existing
>>> > class
>>> > >>> > > without
>>> > >>> > > > > > changing the existing functionality. This will have
>>> two
>>> > >>> > different
>>> > >>> > > > ways
>>> > >>> > > > > > that
>>> > >>> > > > > > insert queries may be handled in the operator.
>>> > >>> > > > > > 3. Add another class which extends from
>>> > >>> JdbcPOJOOutputOperator
>>> > >>> > and
>>> > >>> > > > > have
>>> > >>> > > > > > the update/merge functionality there. (This is not
>>> > >>> recommended.)
>>> > >>> > > > > > 4. Any other approach.
>>> > >>> > > > > >
>>> > >>> > > > > > Please suggest.
>>> > >>> > > > > >
>>> > >>> > > > > > Thanks.
>>> > >>> > > > > >
>>> > >>> > > > > > -Bhupesh.
>>> > >>> > > > > >
>>> > >>> > > > > >
>>> > >>> > > > > > On Mon, Dec 14, 2015 at 11:04 AM, Chandni Singh <
>>> > >>> > > > chandni@datatorrent.com
>>> > >>> > > > > >
>>> > >>> > > > > > wrote:
>>> > >>> > > > > >
>>> > >>> > > > > > > No I don't think we are restricting Malhar to just
>>> abstract
>>> > >>> > > classes.
>>> > >>> > > > > > > Whenever they are couple of use cases that we see quite
>>> > >>> often, we
>>> > >>> > > add
>>> > >>> > > > > > > concrete implementations.
>>> > >>> > > > > > >
>>> > >>> > > > > > > For eg. FileLineInputOperator which is a concrete
>>> > >>> implementation
>>> > >>> > of
>>> > >>> > > > > > > AbstractFileInputOperator. FSSliceReader is an example
>>> as
>>> > >>> well.
>>> > >>> > > > > > >
>>> > >>> > > > > > > In AbstractJdbcOutputOperator case there hasn't been
>>> such
>>> > >>> common
>>> > >>> > > > > > > insert/update query.
>>> > >>> > > > > > >
>>> > >>> > > > > > > Also if you look at the example I provided, it is very
>>> > >>> simple to
>>> > >>> > > > > provide
>>> > >>> > > > > > a
>>> > >>> > > > > > > concrete implementation.
>>> > >>> > > > > > >
>>> > >>> > > > > > > If you would like to change JdbcPOJOOutputOperator to
>>> work
>>> > >>> for
>>> > >>> > > > > > > "UPDATE/MERGE" then please go ahead.
>>> > >>> > > > > > >
>>> > >>> > > > > > > Chandni
>>> > >>> > > > > > >
>>> > >>> > > > > > > On Sun, Dec 13, 2015 at 8:47 PM, Bhupesh Chawda <
>>> > >>> > > > > bhupesh@datatorrent.com
>>> > >>> > > > > > >
>>> > >>> > > > > > > wrote:
>>> > >>> > > > > > >
>>> > >>> > > > > > > > I see. So, just to understand more, do we plan to
>>> keep
>>> > >>> Malhar
>>> > >>> > > > > > restricted
>>> > >>> > > > > > > to
>>> > >>> > > > > > > > the base functionality (as in abstract classes)? And
>>> put
>>> > >>> the
>>> > >>> > > > > > > configuration
>>> > >>> > > > > > > > aspect / concrete implementations in apps that use
>>> these
>>> > >>> > > operators?
>>> > >>> > > > > > > >
>>> > >>> > > > > > > > Thanks.
>>> > >>> > > > > > > > Bhupesh
>>> > >>> > > > > > > >
>>> > >>> > > > > > > > On Sat, Dec 12, 2015 at 5:43 AM, Chandni Singh <
>>> > >>> > > > > > chandni@datatorrent.com>
>>> > >>> > > > > > > > wrote:
>>> > >>> > > > > > > >
>>> > >>> > > > > > > > > Hi,
>>> > >>> > > > > > > > >
>>> > >>> > > > > > > > > Here is an example of doing Upsert with JDBC:
>>> > >>> > > > > > > > >
>>> > >>> > > > > > > > >
>>> > >>> > > > > > > >
>>> > >>> > > > > > >
>>> > >>> > > > > >
>>> > >>> > > > >
>>> > >>> > > >
>>> > >>> > >
>>> > >>> >
>>> > >>>
>>> >
>>> https://github.com/chandnisingh/Malhar/blob/examples/apps/jdbc/src/main/java/com/datatorrent/jdbc/JdbcWriter.java
>>> > >>> > > > > > > > >
>>> > >>> > > > > > > > > Thanks,
>>> > >>> > > > > > > > > Chandni
>>> > >>> > > > > > > > >
>>> > >>> > > > > > > > > On Fri, Dec 11, 2015 at 11:19 AM, Chandni Singh <
>>> > >>> > > > > > > chandni@datatorrent.com
>>> > >>> > > > > > > > >
>>> > >>> > > > > > > > > wrote:
>>> > >>> > > > > > > > >
>>> > >>> > > > > > > > > > The operators are under Malhar/lib/db/jdbc.
>>> > >>> > > > > > > > > >
>>> > >>> > > > > > > > > > Here is one of them:
>>> > >>> > > > > > > > > >
>>> > >>> > > > > > > > > >
>>> > >>> > > > > > > > >
>>> > >>> > > > > > > >
>>> > >>> > > > > > >
>>> > >>> > > > > >
>>> > >>> > > > >
>>> > >>> > > >
>>> > >>> > >
>>> > >>> >
>>> > >>>
>>> >
>>> https://github.com/apache/incubator-apex-malhar/blob/devel-3/library/src/main/java/com/datatorrent/lib/db/jdbc/AbstractJdbcTransactionableOutputOperator.java
>>> > >>> > > > > > > > > >
>>> > >>> > > > > > > > > > They work with any kind PreparedStatement -
>>> insert or
>>> > >>> > update
>>> > >>> > > > > > > > > >
>>> > >>> > > > > > > > > > Chandni
>>> > >>> > > > > > > > > >
>>> > >>> > > > > > > > > >
>>> > >>> > > > > > > > > >
>>> > >>> > > > > > > > > > On Fri, Dec 11, 2015 at 10:59 AM, Bhupesh Chawda
>>> <
>>> > >>> > > > > > > > > bhupesh@datatorrent.com>
>>> > >>> > > > > > > > > > wrote:
>>> > >>> > > > > > > > > >
>>> > >>> > > > > > > > > >> Hi Chandni,
>>> > >>> > > > > > > > > >>
>>> > >>> > > > > > > > > >> I don't see an update query being handled in the
>>> > >>> operator.
>>> > >>> > > > Could
>>> > >>> > > > > > you
>>> > >>> > > > > > > > > >> please
>>> > >>> > > > > > > > > >> point me to the appropriate class?
>>> > >>> > > > > > > > > >> Or did you mean that handling a update query is
>>> > just a
>>> > >>> > > matter
>>> > >>> > > > of
>>> > >>> > > > > > > > > extending
>>> > >>> > > > > > > > > >> the class and providing a concrete
>>> implementation?
>>> > >>> > > > > > > > > >>
>>> > >>> > > > > > > > > >> Thanks.
>>> > >>> > > > > > > > > >> -Bhupesh
>>> > >>> > > > > > > > > >>
>>> > >>> > > > > > > > > >> On Fri, Dec 11, 2015 at 10:42 PM, Chandni Singh
>>> <
>>> > >>> > > > > > > > > chandni@datatorrent.com>
>>> > >>> > > > > > > > > >> wrote:
>>> > >>> > > > > > > > > >>
>>> > >>> > > > > > > > > >> > Hi Bhupesh,
>>> > >>> > > > > > > > > >> >
>>> > >>> > > > > > > > > >> > The current abstract JDBC Output Operators in
>>> > >>> library
>>> > >>> > are
>>> > >>> > > > > > generic
>>> > >>> > > > > > > > and
>>> > >>> > > > > > > > > >> have
>>> > >>> > > > > > > > > >> > already been used in multiple POCs and
>>> > >>> applications. In
>>> > >>> > > fact
>>> > >>> > > > > > this
>>> > >>> > > > > > > > > >> operator
>>> > >>> > > > > > > > > >> > has matured through customer use cases. It is
>>> not
>>> > >>> just
>>> > >>> > an
>>> > >>> > > > > insert
>>> > >>> > > > > > > > > >> operator.
>>> > >>> > > > > > > > > >> > We have used it to perform update and inserts.
>>> > >>> > > > > > > > > >> >
>>> > >>> > > > > > > > > >> > That said, I don't think it is a good idea to
>>> > >>> introduce
>>> > >>> > > > input
>>> > >>> > > > > > > format
>>> > >>> > > > > > > > > in
>>> > >>> > > > > > > > > >> > these abstract implementations. It is
>>> written to
>>> > >>> handle
>>> > >>> > > any
>>> > >>> > > > > > type
>>> > >>> > > > > > > of
>>> > >>> > > > > > > > > >> query,
>>> > >>> > > > > > > > > >> > be it a procedure call (that was an actual
>>> > customer
>>> > >>> use
>>> > >>> > > > case).
>>> > >>> > > > > > > > > >> >
>>> > >>> > > > > > > > > >> > Chandni
>>> > >>> > > > > > > > > >> >
>>> > >>> > > > > > > > > >> > On Fri, Dec 11, 2015 at 2:50 AM, Bhupesh
>>> Chawda <
>>> > >>> > > > > > > > > >> bhupesh@datatorrent.com>
>>> > >>> > > > > > > > > >> > wrote:
>>> > >>> > > > > > > > > >> >
>>> > >>> > > > > > > > > >> > > Hi All,
>>> > >>> > > > > > > > > >> > >
>>> > >>> > > > > > > > > >> > > We are planning to proceed with the
>>> following
>>> > >>> approach
>>> > >>> > > for
>>> > >>> > > > > > JDBC
>>> > >>> > > > > > > > > >> *update*
>>> > >>> > > > > > > > > >> > > operator:
>>> > >>> > > > > > > > > >> > >
>>> > >>> > > > > > > > > >> > > - *Update Query Configuration*
>>> > >>> > > > > > > > > >> > >
>>> > >>> > > > > > > > > >> > >
>>> > >>> > > > > > > > > >> > > - Example Update Query: *update
>>> tableName set
>>> > >>> a =
>>> > >>> > ?**
>>> > >>> > > > > > where b
>>> > >>> > > > > > > > = ?
>>> > >>> > > > > > > > > >> and
>>> > >>> > > > > > > > > >> > c
>>> > >>> > > > > > > > > >> > > > ?;*
>>> > >>> > > > > > > > > >> > > - Example JSON input array for parameter
>>> > >>> > > > instantiations:
>>> > >>> > > > > > > *[{a,
>>> > >>> > > > > > > > > >> > > expression, INTEGER}, {b, expression,
>>> > >>> VARCHAR}, {c,
>>> > >>> > > > > > > expression,
>>> > >>> > > > > > > > > >> > DATE}]*
>>> > >>> > > > > > > > > >> > >
>>> > >>> > > > > > > > > >> > > We are also planning to change the JDBC
>>> Output
>>> > >>> > Operator
>>> > >>> > > in
>>> > >>> > > > > > > Malhar
>>> > >>> > > > > > > > > >> Library
>>> > >>> > > > > > > > > >> > > which currently does just insert. We plan to
>>> > make
>>> > >>> the
>>> > >>> > > > input
>>> > >>> > > > > > > format
>>> > >>> > > > > > > > > >> > > consistent for both insert and update and
>>> hence
>>> > >>> the
>>> > >>> > > change
>>> > >>> > > > > to
>>> > >>> > > > > > > the
>>> > >>> > > > > > > > > >> current
>>> > >>> > > > > > > > > >> > > way of configuration using JSON. Following
>>> would
>>> > >>> be
>>> > >>> > the
>>> > >>> > > > > config
>>> > >>> > > > > > > for
>>> > >>> > > > > > > > > >> > inserts:
>>> > >>> > > > > > > > > >> > >
>>> > >>> > > > > > > > > >> > > - *Insert Query Configuration*
>>> > >>> > > > > > > > > >> > >
>>> > >>> > > > > > > > > >> > >
>>> > >>> > > > > > > > > >> > > - Example Insert Query: *insert into
>>> > tableName
>>> > >>> > values
>>> > >>> > > > (?,
>>> > >>> > > > > > ?,
>>> > >>> > > > > > > > .. ,
>>> > >>> > > > > > > > > >> ?);*
>>> > >>> > > > > > > > > >> > > - Example JSON input array for parameter
>>> > >>> > > > instantiations:
>>> > >>> > > > > > > *[{a,
>>> > >>> > > > > > > > > >> > > expression, INTEGER}, {b, expression,
>>> > >>> VARCHAR}, ..
>>> > >>> > ,
>>> > >>> > > > {c,
>>> > >>> > > > > > > > > >> expression,
>>> > >>> > > > > > > > > >> > > DATE}]*
>>> > >>> > > > > > > > > >> > >
>>> > >>> > > > > > > > > >> > > Please let us know your thoughts.
>>> > >>> > > > > > > > > >> > >
>>> > >>> > > > > > > > > >> > > Thanks.
>>> > >>> > > > > > > > > >> > >
>>> > >>> > > > > > > > > >> > > -Bhupesh
>>> > >>> > > > > > > > > >> > >
>>> > >>> > > > > > > > > >> > >
>>> > >>> > > > > > > > > >> > >
>>> > >>> > > > > > > > > >> > > On Wed, Dec 9, 2015 at 6:38 PM, Bhupesh
>>> Chawda <
>>> > >>> > > > > > > > > >> bhupesh@datatorrent.com>
>>> > >>> > > > > > > > > >> > > wrote:
>>> > >>> > > > > > > > > >> > >
>>> > >>> > > > > > > > > >> > > > Hi All,
>>> > >>> > > > > > > > > >> > > >
>>> > >>> > > > > > > > > >> > > > Would it be a good idea to introduce the
>>> > update
>>> > >>> > > > > > functionality
>>> > >>> > > > > > > to
>>> > >>> > > > > > > > > the
>>> > >>> > > > > > > > > >> > JDBC
>>> > >>> > > > > > > > > >> > > > output operator in Apache Apex Malhar
>>> library.
>>> > >>> > > > > > > > > >> > > >
>>> > >>> > > > > > > > > >> > > > The following are possible approaches:
>>> > >>> > > > > > > > > >> > > >
>>> > >>> > > > > > > > > >> > > > 1. Accept a update query from the user
>>> with
>>> > >>> place
>>> > >>> > > > > holders
>>> > >>> > > > > > > for
>>> > >>> > > > > > > > > >> > values.
>>> > >>> > > > > > > > > >> > > > Example: *update tableName set a = ?,
>>> b = ?
>>> > >>> > where c
>>> > >>> > > > = ?
>>> > >>> > > > > > and
>>> > >>> > > > > > > > d >
>>> > >>> > > > > > > > > >> ?*.
>>> > >>> > > > > > > > > >> > > > Here "?" will be provided by the user
>>> as
>>> > java
>>> > >>> > > > > expressions
>>> > >>> > > > > > > > which
>>> > >>> > > > > > > > > >> will
>>> > >>> > > > > > > > > >> > > be
>>> > >>> > > > > > > > > >> > > > evaluated from the incoming tuple.
>>> > >>> > > > > > > > > >> > > > 2. Another option is to accept in some
>>> > >>> > > configuration
>>> > >>> > > > > > format
>>> > >>> > > > > > > > > >> (json /
>>> > >>> > > > > > > > > >> > > > xml) the following and formulate the
>>> query
>>> > >>> in the
>>> > >>> > > > > > operator.
>>> > >>> > > > > > > > > This
>>> > >>> > > > > > > > > >> can
>>> > >>> > > > > > > > > >> > > become
>>> > >>> > > > > > > > > >> > > > arbitrarily complex.
>>> > >>> > > > > > > > > >> > > > 1. update clause columns
>>> > >>> > > > > > > > > >> > > > 2. update clause expressions
>>> > >>> > > > > > > > > >> > > > 3. where clause columns
>>> > >>> > > > > > > > > >> > > > 4. where clause expressions
>>> > >>> > > > > > > > > >> > > >
>>> > >>> > > > > > > > > >> > > > I am thinking about going ahead with 1.
>>> Please
>>> > >>> let
>>> > >>> > me
>>> > >>> > > > know
>>> > >>> > > > > > if
>>> > >>> > > > > > > > any
>>> > >>> > > > > > > > > >> other
>>> > >>> > > > > > > > > >> > > > option is possible and whether such a
>>> > >>> functionality
>>> > >>> > > > > already
>>> > >>> > > > > > > > exists
>>> > >>> > > > > > > > > >> in
>>> > >>> > > > > > > > > >> > > some
>>> > >>> > > > > > > > > >> > > > other class.
>>> > >>> > > > > > > > > >> > > >
>>> > >>> > > > > > > > > >> > > > Thanks.
>>> > >>> > > > > > > > > >> > > >
>>> > >>> > > > > > > > > >> > > > -Bhupesh
>>> > >>> > > > > > > > > >> > > >
>>> > >>> > > > > > > > > >> > >
>>> > >>> > > > > > > > > >> >
>>> > >>> > > > > > > > > >>
>>> > >>> > > > > > > > > >
>>> > >>> > > > > > > > > >
>>> > >>> > > > > > > > >
>>> > >>> > > > > > > >
>>> > >>> > > > > > >
>>> > >>> > > > > >
>>> > >>> > > > >
>>> > >>> > > >
>>> > >>> > >
>>> > >>> >
>>> > >>>
>>> > >>
>>> > >>
>>> > >
>>> >
>>>
>>
>>
>
Re: Changes to JdbcOutputOperator
Posted by Bhupesh Chawda <bh...@datatorrent.com>.
Hi,
Here are some of the details on what happens when automatic mapping is done
from POJO fields to DB columns ( i.e. when FieldInfo is not provided)
- The reference list of columns is *all* the columns in the database
table.
- If the same field is found in POJO as in DB table, then we include it
in the columns to be inserted and create the corresponding getter from POJO.
- If the same field is not found in the POJO, but the field is a
*nullable* field in the DB, then we drop it from the insert column list.
This means we essentially insert a *null* value for that field.
- If the same field is not found in the POJO and the field is a
*non-nullable* field in the DB, then we throw an exception.
~Bhupesh
On Tue, Mar 15, 2016 at 2:57 PM, Bhupesh Chawda <bh...@datatorrent.com>
wrote:
> Hi All,
>
> Here is the design I am considering for including the additional feature
> as mentioned in the previous email. Please note that this includes the
> previous feedback received on the design.
>
> 1. Rename JdbcPOJOOutputOperator -> *AbstractJdbcPOJOOutputOperator*
> 2. Add *JdbcPOJOInsertOutputOperator* extending from
> *AbstractJdbcPOJOOutputOperator*. This will be used for "*insert*"
> output query.
> 1. If FieldInfo (Mapping of POJO fields to DB columns) is provided
> by the user - then use only these columns to build the insert SQL string.
> Return this insert query as the update command.
> 2. If FieldInfo is not provided by the user - then assume a direct
> mapping between POJO fields and the DB columns. Extract list of columns
> from DB and populate all columns from POJO fields. The POJO fields will be
> assumed to be the same as DB column names.
> 3. Add *JdbcPOJONonInsertOutputOperator *extending from
> *AbstractJdbcPOJOOutputOperator*. This will be used for "*update /
> merge / delete*" output queries. [This design stays the same as
> discussed previously]
> 1. Accept a parametrized SQL string
> 2. Use the FieldInfo provided by the user to populate the
> parameters in the query.
> 3. Execute the query.
>
> Please provide your thoughts on this.
>
> Thanks.
> ~Bhupesh
>
>
> On Mon, Mar 14, 2016 at 6:29 PM, Priyanka Gugale <priyanka@datatorrent.com
> > wrote:
>
>> +1, this is simplifying operator configuration, we should do same for
>> other
>> DB operators as well.
>>
>> -Priyanka
>>
>> On Thu, Mar 10, 2016 at 5:34 PM, Bhupesh Chawda <bh...@datatorrent.com>
>> wrote:
>>
>> > Hi All,
>> >
>> > Apart from extending the JDBC Output operator (for update, merge and
>> > delete), I am planning the following change to the "*insert*"
>> > functionality:
>> >
>> >
>> > - It was pointed out that - if the incoming POJO has fields which
>> are to
>> > be inserted into a database table, the user should not have to
>> specify
>> > any
>> > kind of mapping between POJO columns and database table column names.
>> > This
>> > is possible if the POJO field names are same as the db column names.
>> >
>> >
>> > - Here is what I am planning to do to address this:
>> > - Have a flag which indicates "*No mapping required. Assume same
>> POJO
>> > field names as the DB column names.*"
>> > - If this flag is true, extract DB column names (in addition to
>> the
>> > types, which is done currently) and create getters from POJO based
>> > on the
>> > DB column types.
>> > - Use these getters to populate the parametrized "*insert*" query.
>> >
>> >
>> > Note - Once this is done, the user would not have to specify any field
>> > descriptions. Just the DB table name would be sufficient. This would
>> only
>> > be possible if the DB column names are the same as the field names in
>> the
>> > POJO.
>> > Without this change, "*insert*" will be considered as just another DDL
>> > query like "update" / "delete" / "merge". We accept a parametrized query
>> > and a mapping from the user for POJO field names to DB column names + DB
>> > column types.
>> >
>> > Thanks.
>> > Bhupesh
>> >
>> >
>> > On Wed, Dec 30, 2015 at 12:56 PM, Bhupesh Chawda <
>> bhupesh@datatorrent.com>
>> > wrote:
>> >
>> > > Also, since we are not creating separate operators for insert and
>> > > update/merge, it seems we don't need an abstract class. We can
>> directly
>> > > modify JdbcPOJOOutputOperator.
>> > >
>> > > -Bhupesh
>> > >
>> > > On Wed, Dec 30, 2015 at 11:17 AM, Bhupesh Chawda <
>> > bhupesh@datatorrent.com>
>> > > wrote:
>> > >
>> > >> Also, a note regarding accepting fieldInfo objects:
>> > >>
>> > >> FieldInfo has fields for java type of the column, but not the SQL
>> data
>> > >> type which is needed to set the parameters in the SQL statement. This
>> > still
>> > >> needs to be derived from the database (as in insert).
>> > >> In more complex scenarios, as mentioned earlier, this may not always
>> be
>> > >> possible. In this case we have the following options:
>> > >>
>> > >> 1. Accept the SQL data types from the user for the parameters
>> ("?")
>> > >> in a new data structure.
>> > >> 2. Accept the JSON structure as specified earlier.
>> > >> 3. Modify FieldInfo to have an additional optional field which
>> > >> indicates the SQL data type of the parameter ("?")
>> > >>
>> > >> I am planning to go ahead with option 3.
>> > >>
>> > >> Comments?
>> > >>
>> > >> -Bhupesh
>> > >>
>> > >>
>> > >>
>> > >> On Mon, Dec 28, 2015 at 11:26 PM, Chandni Singh <
>> > chandni@datatorrent.com>
>> > >> wrote:
>> > >>
>> > >>> Yeah that sounds good.
>> > >>>
>> > >>> Chandni
>> > >>>
>> > >>> On Mon, Dec 28, 2015 at 2:46 AM, Bhupesh Chawda <
>> > bhupesh@datatorrent.com
>> > >>> >
>> > >>> wrote:
>> > >>>
>> > >>> > Thanks Chandni for the comments.
>> > >>> >
>> > >>> > Additionally I think, we should do away with constructing the SQL
>> > >>> query in
>> > >>> > the operator. This is because it is only possible in case of
>> simple
>> > >>> insert
>> > >>> > statements. In case a where clause is needed in the insert
>> statement,
>> > >>> we
>> > >>> > cannot construct the SQL easily. If we are accepting a
>> parametrized
>> > >>> query
>> > >>> > from the user for update/merge, why not do the same for insert
>> > >>> statements
>> > >>> > as well? Then the hierarchy would look like:
>> > >>> > - AbstractJdbcPOJOOutputOperator (As suggested)
>> > >>> > -- JdbcPOJOOutputOperator (Takes care of all statements insert,
>> > update,
>> > >>> > merge, delete)
>> > >>> >
>> > >>> > We don't need a separate operator for inserts and update/merge.
>> > >>> >
>> > >>> > Thanks.
>> > >>> > -Bhupesh
>> > >>> >
>> > >>> >
>> > >>> > On Mon, Dec 28, 2015 at 3:32 PM, Chandni Singh <
>> > >>> chandni@datatorrent.com>
>> > >>> > wrote:
>> > >>> >
>> > >>> > > 1. FieldInfo, is ultimately a custom object and any user who
>> uses
>> > >>> this
>> > >>> > > operator has to construct an object, populate it and then use
>> > it.
>> > >>> We
>> > >>> > are
>> > >>> > > trying to avoid using any custom object and allow any user to
>> > use
>> > >>> the
>> > >>> > > operator without writing any extra code; just configuration.
>> > >>> > > FieldInfo is a way to provide configuration in a UI friendly
>> way.
>> > >>> > Providing
>> > >>> > > configuration as JSON is not UI friendly.
>> > >>> > >
>> > >>> > > 2. In case of update / merge, we need what SQL data types
>> that
>> > the
>> > >>> > > expression provided by the user would evaluate to. In case of
>> > >>> insert
>> > >>> > we
>> > >>> > > can
>> > >>> > > go and fetch the data types of the columns directly from DB.
>> > >>> However,
>> > >>> > > the
>> > >>> > > same is not possible for custom expressions; "avg(salary)"
>> for
>> > >>> > instance.
>> > >>> > > Ok so here is where you can make a change.
>> > >>> > > - JDBCPojoOutput can be renamed to
>> AbstractJDBCPojoOutpuOperator.
>> > >>> > > - Abstraction is to fetch the type of column.
>> > >>> > > - Add a concrete JDBCPojoInsertOutput that derives the types of
>> > >>> columns
>> > >>> > > directly from DB. Please note that FieldInfo can also provide
>> type
>> > of
>> > >>> > > derived column.
>> > >>> > >
>> > >>> > >
>> > >>> > > You mentioned "We are trying to avoid using any custom object
>> and
>> > >>> allow
>> > >>> > any
>> > >>> > > user to use the
>> > >>> > > operator without writing any extra code".
>> > >>> > > This I think is specific to your use case. You can create an
>> > >>> extension of
>> > >>> > > the above which takes JSON blob and creates FieldInfos from it.
>> > >>> > >
>> > >>> > > Chandni
>> > >>> > >
>> > >>> > >
>> > >>> > >
>> > >>> > >
>> > >>> > >
>> > >>> > > On Mon, Dec 28, 2015 at 1:48 AM, Bhupesh Chawda <
>> > >>> bhupesh@datatorrent.com
>> > >>> > >
>> > >>> > > wrote:
>> > >>> > >
>> > >>> > > > Hi Chandni,
>> > >>> > > >
>> > >>> > > > Following are the issues:
>> > >>> > > >
>> > >>> > > > 1. FieldInfo, is ultimately a custom object and any user
>> who
>> > >>> uses
>> > >>> > this
>> > >>> > > > operator has to construct an object, populate it and then
>> use
>> > >>> it. We
>> > >>> > > are
>> > >>> > > > trying to avoid using any custom object and allow any user
>> to
>> > >>> use
>> > >>> > the
>> > >>> > > > operator without writing any extra code; just
>> configuration.
>> > >>> > > > 2. In case of update / merge, we need what SQL data types
>> that
>> > >>> the
>> > >>> > > > expression provided by the user would evaluate to. In case
>> of
>> > >>> insert
>> > >>> > > we
>> > >>> > > > can
>> > >>> > > > go and fetch the data types of the columns directly from
>> DB.
>> > >>> > However,
>> > >>> > > > the
>> > >>> > > > same is not possible for custom expressions; "avg(salary)"
>> for
>> > >>> > > instance.
>> > >>> > > >
>> > >>> > > > Thanks.
>> > >>> > > >
>> > >>> > > > -Bhupesh
>> > >>> > > >
>> > >>> > > >
>> > >>> > > > On Mon, Dec 28, 2015 at 2:57 PM, Chandni Singh <
>> > >>> > chandni@datatorrent.com>
>> > >>> > > > wrote:
>> > >>> > > >
>> > >>> > > > > Hi Bhupesh,
>> > >>> > > > >
>> > >>> > > > > JDBCPojoOutputOperator was written for a demo and therefore
>> it
>> > >>> was
>> > >>> > > marked
>> > >>> > > > > Evolving which is why I had mentioned that you should feel
>> free
>> > >>> to
>> > >>> > > modify
>> > >>> > > > > it.
>> > >>> > > > >
>> > >>> > > > > I think an insert query can be as complex as any other
>> query.
>> > It
>> > >>> uses
>> > >>> > > > > FieldInfo because in the app builder it is easy for the
>> user to
>> > >>> > provide
>> > >>> > > > > that instead of JSON String.
>> > >>> > > > >
>> > >>> > > > > Can you please provide specifics about what it is that you
>> find
>> > >>> > > difficult
>> > >>> > > > > to change/implement for providing update/merge/delete
>> support
>> > in
>> > >>> > > > > JDBCPojoOutputOperator?
>> > >>> > > > >
>> > >>> > > > > Chandni
>> > >>> > > > >
>> > >>> > > > > On Mon, Dec 28, 2015 at 1:09 AM, Bhupesh Chawda <
>> > >>> > > bhupesh@datatorrent.com
>> > >>> > > > >
>> > >>> > > > > wrote:
>> > >>> > > > >
>> > >>> > > > > > Hi All,
>> > >>> > > > > >
>> > >>> > > > > > It has been pointed out that adding another class for
>> > handling
>> > >>> > > update /
>> > >>> > > > > > merge queries would not be a good option.
>> > >>> > > > > >
>> > >>> > > > > > Here are the current implementation details:
>> > >>> > > > > >
>> > >>> > > > > > - We have an existing class: JdbcPOJOOutputOperator
>> which
>> > >>> > accepts
>> > >>> > > a
>> > >>> > > > > list
>> > >>> > > > > > of FieldInfo objects. Each element of this list
>> indicates
>> > >>> the
>> > >>> > > > details
>> > >>> > > > > > (column name, pojo field expression and datatype) of
>> > fields
>> > >>> that
>> > >>> > > > need
>> > >>> > > > > > to be
>> > >>> > > > > > inserted. Using this, the operator formulates the
>> insert
>> > >>> query
>> > >>> > in
>> > >>> > > > the
>> > >>> > > > > > setup
>> > >>> > > > > > method and identifies the sql datatypes of these
>> columns
>> > >>> from
>> > >>> > the
>> > >>> > > > > > database
>> > >>> > > > > > using the table name.
>> > >>> > > > > >
>> > >>> > > > > >
>> > >>> > > > > > - Now, coming to the update / merge feature, it is
>> > >>> difficult to
>> > >>> > > > > > formulate the update / merge query in the operator
>> logic
>> > >>> due to
>> > >>> > > the
>> > >>> > > > > > complex
>> > >>> > > > > > structure of these statements. For this reason, we
>> plan to
>> > >>> take
>> > >>> > a
>> > >>> > > > > > parametrized SQL query from the user. This may look
>> like:
>> > >>> > *"update
>> > >>> > > > > table
>> > >>> > > > > > set x = ?, y = ? where z + w > ? and a == 1;"*. Such
>> > >>> statements
>> > >>> > > can
>> > >>> > > > be
>> > >>> > > > > > accepted from the user in addition to a json string
>> which
>> > >>> > > indicates
>> > >>> > > > > the
>> > >>> > > > > > details for the parameters: *column name, the pojo
>> > >>> expression
>> > >>> > and
>> > >>> > > > the
>> > >>> > > > > > sql data type* of the expression. Note that this
>> > >>> information is
>> > >>> > > > > similar
>> > >>> > > > > > to the FieldInfo object, but is a string which can be
>> > >>> configured
>> > >>> > > > > easily
>> > >>> > > > > > by
>> > >>> > > > > > the user. Also note that the data type which is
>> accepted
>> > is
>> > >>> the
>> > >>> > > SQL
>> > >>> > > > > data
>> > >>> > > > > > type. Using this info we can populate the parametrized
>> > >>> query and
>> > >>> > > run
>> > >>> > > > > it
>> > >>> > > > > > based on the incoming POJO.
>> > >>> > > > > >
>> > >>> > > > > > The second approach is able to handle all kinds of queries
>> > >>> (insert
>> > >>> > /
>> > >>> > > > > update
>> > >>> > > > > > / merge / delete). However, since we already have the
>> > >>> > > > > > JdbcPOJOOutputOperator, we would like to merge the new
>> > >>> > functionality
>> > >>> > > > into
>> > >>> > > > > > the same class.
>> > >>> > > > > >
>> > >>> > > > > > Here we have the following options:
>> > >>> > > > > >
>> > >>> > > > > > 1. Change the existing class (JdbcPOJOOutputOperator)
>> to
>> > the
>> > >>> > > second
>> > >>> > > > > > approach which is more generic and also handles
>> inserts.
>> > >>> > > > > > 2. Add the update/ merge functionality to the existing
>> > class
>> > >>> > > without
>> > >>> > > > > > changing the existing functionality. This will have two
>> > >>> > different
>> > >>> > > > ways
>> > >>> > > > > > that
>> > >>> > > > > > insert queries may be handled in the operator.
>> > >>> > > > > > 3. Add another class which extends from
>> > >>> JdbcPOJOOutputOperator
>> > >>> > and
>> > >>> > > > > have
>> > >>> > > > > > the update/merge functionality there. (This is not
>> > >>> recommended.)
>> > >>> > > > > > 4. Any other approach.
>> > >>> > > > > >
>> > >>> > > > > > Please suggest.
>> > >>> > > > > >
>> > >>> > > > > > Thanks.
>> > >>> > > > > >
>> > >>> > > > > > -Bhupesh.
>> > >>> > > > > >
>> > >>> > > > > >
>> > >>> > > > > > On Mon, Dec 14, 2015 at 11:04 AM, Chandni Singh <
>> > >>> > > > chandni@datatorrent.com
>> > >>> > > > > >
>> > >>> > > > > > wrote:
>> > >>> > > > > >
>> > >>> > > > > > > No I don't think we are restricting Malhar to just
>> abstract
>> > >>> > > classes.
>> > >>> > > > > > > Whenever they are couple of use cases that we see quite
>> > >>> often, we
>> > >>> > > add
>> > >>> > > > > > > concrete implementations.
>> > >>> > > > > > >
>> > >>> > > > > > > For eg. FileLineInputOperator which is a concrete
>> > >>> implementation
>> > >>> > of
>> > >>> > > > > > > AbstractFileInputOperator. FSSliceReader is an example
>> as
>> > >>> well.
>> > >>> > > > > > >
>> > >>> > > > > > > In AbstractJdbcOutputOperator case there hasn't been
>> such
>> > >>> common
>> > >>> > > > > > > insert/update query.
>> > >>> > > > > > >
>> > >>> > > > > > > Also if you look at the example I provided, it is very
>> > >>> simple to
>> > >>> > > > > provide
>> > >>> > > > > > a
>> > >>> > > > > > > concrete implementation.
>> > >>> > > > > > >
>> > >>> > > > > > > If you would like to change JdbcPOJOOutputOperator to
>> work
>> > >>> for
>> > >>> > > > > > > "UPDATE/MERGE" then please go ahead.
>> > >>> > > > > > >
>> > >>> > > > > > > Chandni
>> > >>> > > > > > >
>> > >>> > > > > > > On Sun, Dec 13, 2015 at 8:47 PM, Bhupesh Chawda <
>> > >>> > > > > bhupesh@datatorrent.com
>> > >>> > > > > > >
>> > >>> > > > > > > wrote:
>> > >>> > > > > > >
>> > >>> > > > > > > > I see. So, just to understand more, do we plan to keep
>> > >>> Malhar
>> > >>> > > > > > restricted
>> > >>> > > > > > > to
>> > >>> > > > > > > > the base functionality (as in abstract classes)? And
>> put
>> > >>> the
>> > >>> > > > > > > configuration
>> > >>> > > > > > > > aspect / concrete implementations in apps that use
>> these
>> > >>> > > operators?
>> > >>> > > > > > > >
>> > >>> > > > > > > > Thanks.
>> > >>> > > > > > > > Bhupesh
>> > >>> > > > > > > >
>> > >>> > > > > > > > On Sat, Dec 12, 2015 at 5:43 AM, Chandni Singh <
>> > >>> > > > > > chandni@datatorrent.com>
>> > >>> > > > > > > > wrote:
>> > >>> > > > > > > >
>> > >>> > > > > > > > > Hi,
>> > >>> > > > > > > > >
>> > >>> > > > > > > > > Here is an example of doing Upsert with JDBC:
>> > >>> > > > > > > > >
>> > >>> > > > > > > > >
>> > >>> > > > > > > >
>> > >>> > > > > > >
>> > >>> > > > > >
>> > >>> > > > >
>> > >>> > > >
>> > >>> > >
>> > >>> >
>> > >>>
>> >
>> https://github.com/chandnisingh/Malhar/blob/examples/apps/jdbc/src/main/java/com/datatorrent/jdbc/JdbcWriter.java
>> > >>> > > > > > > > >
>> > >>> > > > > > > > > Thanks,
>> > >>> > > > > > > > > Chandni
>> > >>> > > > > > > > >
>> > >>> > > > > > > > > On Fri, Dec 11, 2015 at 11:19 AM, Chandni Singh <
>> > >>> > > > > > > chandni@datatorrent.com
>> > >>> > > > > > > > >
>> > >>> > > > > > > > > wrote:
>> > >>> > > > > > > > >
>> > >>> > > > > > > > > > The operators are under Malhar/lib/db/jdbc.
>> > >>> > > > > > > > > >
>> > >>> > > > > > > > > > Here is one of them:
>> > >>> > > > > > > > > >
>> > >>> > > > > > > > > >
>> > >>> > > > > > > > >
>> > >>> > > > > > > >
>> > >>> > > > > > >
>> > >>> > > > > >
>> > >>> > > > >
>> > >>> > > >
>> > >>> > >
>> > >>> >
>> > >>>
>> >
>> https://github.com/apache/incubator-apex-malhar/blob/devel-3/library/src/main/java/com/datatorrent/lib/db/jdbc/AbstractJdbcTransactionableOutputOperator.java
>> > >>> > > > > > > > > >
>> > >>> > > > > > > > > > They work with any kind PreparedStatement -
>> insert or
>> > >>> > update
>> > >>> > > > > > > > > >
>> > >>> > > > > > > > > > Chandni
>> > >>> > > > > > > > > >
>> > >>> > > > > > > > > >
>> > >>> > > > > > > > > >
>> > >>> > > > > > > > > > On Fri, Dec 11, 2015 at 10:59 AM, Bhupesh Chawda <
>> > >>> > > > > > > > > bhupesh@datatorrent.com>
>> > >>> > > > > > > > > > wrote:
>> > >>> > > > > > > > > >
>> > >>> > > > > > > > > >> Hi Chandni,
>> > >>> > > > > > > > > >>
>> > >>> > > > > > > > > >> I don't see an update query being handled in the
>> > >>> operator.
>> > >>> > > > Could
>> > >>> > > > > > you
>> > >>> > > > > > > > > >> please
>> > >>> > > > > > > > > >> point me to the appropriate class?
>> > >>> > > > > > > > > >> Or did you mean that handling a update query is
>> > just a
>> > >>> > > matter
>> > >>> > > > of
>> > >>> > > > > > > > > extending
>> > >>> > > > > > > > > >> the class and providing a concrete
>> implementation?
>> > >>> > > > > > > > > >>
>> > >>> > > > > > > > > >> Thanks.
>> > >>> > > > > > > > > >> -Bhupesh
>> > >>> > > > > > > > > >>
>> > >>> > > > > > > > > >> On Fri, Dec 11, 2015 at 10:42 PM, Chandni Singh <
>> > >>> > > > > > > > > chandni@datatorrent.com>
>> > >>> > > > > > > > > >> wrote:
>> > >>> > > > > > > > > >>
>> > >>> > > > > > > > > >> > Hi Bhupesh,
>> > >>> > > > > > > > > >> >
>> > >>> > > > > > > > > >> > The current abstract JDBC Output Operators in
>> > >>> library
>> > >>> > are
>> > >>> > > > > > generic
>> > >>> > > > > > > > and
>> > >>> > > > > > > > > >> have
>> > >>> > > > > > > > > >> > already been used in multiple POCs and
>> > >>> applications. In
>> > >>> > > fact
>> > >>> > > > > > this
>> > >>> > > > > > > > > >> operator
>> > >>> > > > > > > > > >> > has matured through customer use cases. It is
>> not
>> > >>> just
>> > >>> > an
>> > >>> > > > > insert
>> > >>> > > > > > > > > >> operator.
>> > >>> > > > > > > > > >> > We have used it to perform update and inserts.
>> > >>> > > > > > > > > >> >
>> > >>> > > > > > > > > >> > That said, I don't think it is a good idea to
>> > >>> introduce
>> > >>> > > > input
>> > >>> > > > > > > format
>> > >>> > > > > > > > > in
>> > >>> > > > > > > > > >> > these abstract implementations. It is written
>> to
>> > >>> handle
>> > >>> > > any
>> > >>> > > > > > type
>> > >>> > > > > > > of
>> > >>> > > > > > > > > >> query,
>> > >>> > > > > > > > > >> > be it a procedure call (that was an actual
>> > customer
>> > >>> use
>> > >>> > > > case).
>> > >>> > > > > > > > > >> >
>> > >>> > > > > > > > > >> > Chandni
>> > >>> > > > > > > > > >> >
>> > >>> > > > > > > > > >> > On Fri, Dec 11, 2015 at 2:50 AM, Bhupesh
>> Chawda <
>> > >>> > > > > > > > > >> bhupesh@datatorrent.com>
>> > >>> > > > > > > > > >> > wrote:
>> > >>> > > > > > > > > >> >
>> > >>> > > > > > > > > >> > > Hi All,
>> > >>> > > > > > > > > >> > >
>> > >>> > > > > > > > > >> > > We are planning to proceed with the following
>> > >>> approach
>> > >>> > > for
>> > >>> > > > > > JDBC
>> > >>> > > > > > > > > >> *update*
>> > >>> > > > > > > > > >> > > operator:
>> > >>> > > > > > > > > >> > >
>> > >>> > > > > > > > > >> > > - *Update Query Configuration*
>> > >>> > > > > > > > > >> > >
>> > >>> > > > > > > > > >> > >
>> > >>> > > > > > > > > >> > > - Example Update Query: *update tableName
>> set
>> > >>> a =
>> > >>> > ?**
>> > >>> > > > > > where b
>> > >>> > > > > > > > = ?
>> > >>> > > > > > > > > >> and
>> > >>> > > > > > > > > >> > c
>> > >>> > > > > > > > > >> > > > ?;*
>> > >>> > > > > > > > > >> > > - Example JSON input array for parameter
>> > >>> > > > instantiations:
>> > >>> > > > > > > *[{a,
>> > >>> > > > > > > > > >> > > expression, INTEGER}, {b, expression,
>> > >>> VARCHAR}, {c,
>> > >>> > > > > > > expression,
>> > >>> > > > > > > > > >> > DATE}]*
>> > >>> > > > > > > > > >> > >
>> > >>> > > > > > > > > >> > > We are also planning to change the JDBC
>> Output
>> > >>> > Operator
>> > >>> > > in
>> > >>> > > > > > > Malhar
>> > >>> > > > > > > > > >> Library
>> > >>> > > > > > > > > >> > > which currently does just insert. We plan to
>> > make
>> > >>> the
>> > >>> > > > input
>> > >>> > > > > > > format
>> > >>> > > > > > > > > >> > > consistent for both insert and update and
>> hence
>> > >>> the
>> > >>> > > change
>> > >>> > > > > to
>> > >>> > > > > > > the
>> > >>> > > > > > > > > >> current
>> > >>> > > > > > > > > >> > > way of configuration using JSON. Following
>> would
>> > >>> be
>> > >>> > the
>> > >>> > > > > config
>> > >>> > > > > > > for
>> > >>> > > > > > > > > >> > inserts:
>> > >>> > > > > > > > > >> > >
>> > >>> > > > > > > > > >> > > - *Insert Query Configuration*
>> > >>> > > > > > > > > >> > >
>> > >>> > > > > > > > > >> > >
>> > >>> > > > > > > > > >> > > - Example Insert Query: *insert into
>> > tableName
>> > >>> > values
>> > >>> > > > (?,
>> > >>> > > > > > ?,
>> > >>> > > > > > > > .. ,
>> > >>> > > > > > > > > >> ?);*
>> > >>> > > > > > > > > >> > > - Example JSON input array for parameter
>> > >>> > > > instantiations:
>> > >>> > > > > > > *[{a,
>> > >>> > > > > > > > > >> > > expression, INTEGER}, {b, expression,
>> > >>> VARCHAR}, ..
>> > >>> > ,
>> > >>> > > > {c,
>> > >>> > > > > > > > > >> expression,
>> > >>> > > > > > > > > >> > > DATE}]*
>> > >>> > > > > > > > > >> > >
>> > >>> > > > > > > > > >> > > Please let us know your thoughts.
>> > >>> > > > > > > > > >> > >
>> > >>> > > > > > > > > >> > > Thanks.
>> > >>> > > > > > > > > >> > >
>> > >>> > > > > > > > > >> > > -Bhupesh
>> > >>> > > > > > > > > >> > >
>> > >>> > > > > > > > > >> > >
>> > >>> > > > > > > > > >> > >
>> > >>> > > > > > > > > >> > > On Wed, Dec 9, 2015 at 6:38 PM, Bhupesh
>> Chawda <
>> > >>> > > > > > > > > >> bhupesh@datatorrent.com>
>> > >>> > > > > > > > > >> > > wrote:
>> > >>> > > > > > > > > >> > >
>> > >>> > > > > > > > > >> > > > Hi All,
>> > >>> > > > > > > > > >> > > >
>> > >>> > > > > > > > > >> > > > Would it be a good idea to introduce the
>> > update
>> > >>> > > > > > functionality
>> > >>> > > > > > > to
>> > >>> > > > > > > > > the
>> > >>> > > > > > > > > >> > JDBC
>> > >>> > > > > > > > > >> > > > output operator in Apache Apex Malhar
>> library.
>> > >>> > > > > > > > > >> > > >
>> > >>> > > > > > > > > >> > > > The following are possible approaches:
>> > >>> > > > > > > > > >> > > >
>> > >>> > > > > > > > > >> > > > 1. Accept a update query from the user
>> with
>> > >>> place
>> > >>> > > > > holders
>> > >>> > > > > > > for
>> > >>> > > > > > > > > >> > values.
>> > >>> > > > > > > > > >> > > > Example: *update tableName set a = ?, b
>> = ?
>> > >>> > where c
>> > >>> > > > = ?
>> > >>> > > > > > and
>> > >>> > > > > > > > d >
>> > >>> > > > > > > > > >> ?*.
>> > >>> > > > > > > > > >> > > > Here "?" will be provided by the user as
>> > java
>> > >>> > > > > expressions
>> > >>> > > > > > > > which
>> > >>> > > > > > > > > >> will
>> > >>> > > > > > > > > >> > > be
>> > >>> > > > > > > > > >> > > > evaluated from the incoming tuple.
>> > >>> > > > > > > > > >> > > > 2. Another option is to accept in some
>> > >>> > > configuration
>> > >>> > > > > > format
>> > >>> > > > > > > > > >> (json /
>> > >>> > > > > > > > > >> > > > xml) the following and formulate the
>> query
>> > >>> in the
>> > >>> > > > > > operator.
>> > >>> > > > > > > > > This
>> > >>> > > > > > > > > >> can
>> > >>> > > > > > > > > >> > > become
>> > >>> > > > > > > > > >> > > > arbitrarily complex.
>> > >>> > > > > > > > > >> > > > 1. update clause columns
>> > >>> > > > > > > > > >> > > > 2. update clause expressions
>> > >>> > > > > > > > > >> > > > 3. where clause columns
>> > >>> > > > > > > > > >> > > > 4. where clause expressions
>> > >>> > > > > > > > > >> > > >
>> > >>> > > > > > > > > >> > > > I am thinking about going ahead with 1.
>> Please
>> > >>> let
>> > >>> > me
>> > >>> > > > know
>> > >>> > > > > > if
>> > >>> > > > > > > > any
>> > >>> > > > > > > > > >> other
>> > >>> > > > > > > > > >> > > > option is possible and whether such a
>> > >>> functionality
>> > >>> > > > > already
>> > >>> > > > > > > > exists
>> > >>> > > > > > > > > >> in
>> > >>> > > > > > > > > >> > > some
>> > >>> > > > > > > > > >> > > > other class.
>> > >>> > > > > > > > > >> > > >
>> > >>> > > > > > > > > >> > > > Thanks.
>> > >>> > > > > > > > > >> > > >
>> > >>> > > > > > > > > >> > > > -Bhupesh
>> > >>> > > > > > > > > >> > > >
>> > >>> > > > > > > > > >> > >
>> > >>> > > > > > > > > >> >
>> > >>> > > > > > > > > >>
>> > >>> > > > > > > > > >
>> > >>> > > > > > > > > >
>> > >>> > > > > > > > >
>> > >>> > > > > > > >
>> > >>> > > > > > >
>> > >>> > > > > >
>> > >>> > > > >
>> > >>> > > >
>> > >>> > >
>> > >>> >
>> > >>>
>> > >>
>> > >>
>> > >
>> >
>>
>
>
Re: Changes to JdbcOutputOperator
Posted by Bhupesh Chawda <bh...@datatorrent.com>.
Hi All,
Here is the design I am considering for including the additional feature as
mentioned in the previous email. Please note that this includes the
previous feedback received on the design.
1. Rename JdbcPOJOOutputOperator -> *AbstractJdbcPOJOOutputOperator*
2. Add *JdbcPOJOInsertOutputOperator* extending from
*AbstractJdbcPOJOOutputOperator*. This will be used for "*insert*"
output query.
1. If FieldInfo (Mapping of POJO fields to DB columns) is provided by
the user - then use only these columns to build the insert SQL string.
Return this insert query as the update command.
2. If FieldInfo is not provided by the user - then assume a direct
mapping between POJO fields and the DB columns. Extract list of columns
from DB and populate all columns from POJO fields. The POJO
fields will be
assumed to be the same as DB column names.
3. Add *JdbcPOJONonInsertOutputOperator *extending from
*AbstractJdbcPOJOOutputOperator*. This will be used for "*update / merge
/ delete*" output queries. [This design stays the same as discussed
previously]
1. Accept a parametrized SQL string
2. Use the FieldInfo provided by the user to populate the parameters
in the query.
3. Execute the query.
Please provide your thoughts on this.
Thanks.
~Bhupesh
On Mon, Mar 14, 2016 at 6:29 PM, Priyanka Gugale <pr...@datatorrent.com>
wrote:
> +1, this is simplifying operator configuration, we should do same for other
> DB operators as well.
>
> -Priyanka
>
> On Thu, Mar 10, 2016 at 5:34 PM, Bhupesh Chawda <bh...@datatorrent.com>
> wrote:
>
> > Hi All,
> >
> > Apart from extending the JDBC Output operator (for update, merge and
> > delete), I am planning the following change to the "*insert*"
> > functionality:
> >
> >
> > - It was pointed out that - if the incoming POJO has fields which are
> to
> > be inserted into a database table, the user should not have to specify
> > any
> > kind of mapping between POJO columns and database table column names.
> > This
> > is possible if the POJO field names are same as the db column names.
> >
> >
> > - Here is what I am planning to do to address this:
> > - Have a flag which indicates "*No mapping required. Assume same
> POJO
> > field names as the DB column names.*"
> > - If this flag is true, extract DB column names (in addition to the
> > types, which is done currently) and create getters from POJO based
> > on the
> > DB column types.
> > - Use these getters to populate the parametrized "*insert*" query.
> >
> >
> > Note - Once this is done, the user would not have to specify any field
> > descriptions. Just the DB table name would be sufficient. This would only
> > be possible if the DB column names are the same as the field names in the
> > POJO.
> > Without this change, "*insert*" will be considered as just another DDL
> > query like "update" / "delete" / "merge". We accept a parametrized query
> > and a mapping from the user for POJO field names to DB column names + DB
> > column types.
> >
> > Thanks.
> > Bhupesh
> >
> >
> > On Wed, Dec 30, 2015 at 12:56 PM, Bhupesh Chawda <
> bhupesh@datatorrent.com>
> > wrote:
> >
> > > Also, since we are not creating separate operators for insert and
> > > update/merge, it seems we don't need an abstract class. We can directly
> > > modify JdbcPOJOOutputOperator.
> > >
> > > -Bhupesh
> > >
> > > On Wed, Dec 30, 2015 at 11:17 AM, Bhupesh Chawda <
> > bhupesh@datatorrent.com>
> > > wrote:
> > >
> > >> Also, a note regarding accepting fieldInfo objects:
> > >>
> > >> FieldInfo has fields for java type of the column, but not the SQL data
> > >> type which is needed to set the parameters in the SQL statement. This
> > still
> > >> needs to be derived from the database (as in insert).
> > >> In more complex scenarios, as mentioned earlier, this may not always
> be
> > >> possible. In this case we have the following options:
> > >>
> > >> 1. Accept the SQL data types from the user for the parameters ("?")
> > >> in a new data structure.
> > >> 2. Accept the JSON structure as specified earlier.
> > >> 3. Modify FieldInfo to have an additional optional field which
> > >> indicates the SQL data type of the parameter ("?")
> > >>
> > >> I am planning to go ahead with option 3.
> > >>
> > >> Comments?
> > >>
> > >> -Bhupesh
> > >>
> > >>
> > >>
> > >> On Mon, Dec 28, 2015 at 11:26 PM, Chandni Singh <
> > chandni@datatorrent.com>
> > >> wrote:
> > >>
> > >>> Yeah that sounds good.
> > >>>
> > >>> Chandni
> > >>>
> > >>> On Mon, Dec 28, 2015 at 2:46 AM, Bhupesh Chawda <
> > bhupesh@datatorrent.com
> > >>> >
> > >>> wrote:
> > >>>
> > >>> > Thanks Chandni for the comments.
> > >>> >
> > >>> > Additionally I think, we should do away with constructing the SQL
> > >>> query in
> > >>> > the operator. This is because it is only possible in case of simple
> > >>> insert
> > >>> > statements. In case a where clause is needed in the insert
> statement,
> > >>> we
> > >>> > cannot construct the SQL easily. If we are accepting a parametrized
> > >>> query
> > >>> > from the user for update/merge, why not do the same for insert
> > >>> statements
> > >>> > as well? Then the hierarchy would look like:
> > >>> > - AbstractJdbcPOJOOutputOperator (As suggested)
> > >>> > -- JdbcPOJOOutputOperator (Takes care of all statements insert,
> > update,
> > >>> > merge, delete)
> > >>> >
> > >>> > We don't need a separate operator for inserts and update/merge.
> > >>> >
> > >>> > Thanks.
> > >>> > -Bhupesh
> > >>> >
> > >>> >
> > >>> > On Mon, Dec 28, 2015 at 3:32 PM, Chandni Singh <
> > >>> chandni@datatorrent.com>
> > >>> > wrote:
> > >>> >
> > >>> > > 1. FieldInfo, is ultimately a custom object and any user who
> uses
> > >>> this
> > >>> > > operator has to construct an object, populate it and then use
> > it.
> > >>> We
> > >>> > are
> > >>> > > trying to avoid using any custom object and allow any user to
> > use
> > >>> the
> > >>> > > operator without writing any extra code; just configuration.
> > >>> > > FieldInfo is a way to provide configuration in a UI friendly way.
> > >>> > Providing
> > >>> > > configuration as JSON is not UI friendly.
> > >>> > >
> > >>> > > 2. In case of update / merge, we need what SQL data types that
> > the
> > >>> > > expression provided by the user would evaluate to. In case of
> > >>> insert
> > >>> > we
> > >>> > > can
> > >>> > > go and fetch the data types of the columns directly from DB.
> > >>> However,
> > >>> > > the
> > >>> > > same is not possible for custom expressions; "avg(salary)" for
> > >>> > instance.
> > >>> > > Ok so here is where you can make a change.
> > >>> > > - JDBCPojoOutput can be renamed to AbstractJDBCPojoOutpuOperator.
> > >>> > > - Abstraction is to fetch the type of column.
> > >>> > > - Add a concrete JDBCPojoInsertOutput that derives the types of
> > >>> columns
> > >>> > > directly from DB. Please note that FieldInfo can also provide
> type
> > of
> > >>> > > derived column.
> > >>> > >
> > >>> > >
> > >>> > > You mentioned "We are trying to avoid using any custom object and
> > >>> allow
> > >>> > any
> > >>> > > user to use the
> > >>> > > operator without writing any extra code".
> > >>> > > This I think is specific to your use case. You can create an
> > >>> extension of
> > >>> > > the above which takes JSON blob and creates FieldInfos from it.
> > >>> > >
> > >>> > > Chandni
> > >>> > >
> > >>> > >
> > >>> > >
> > >>> > >
> > >>> > >
> > >>> > > On Mon, Dec 28, 2015 at 1:48 AM, Bhupesh Chawda <
> > >>> bhupesh@datatorrent.com
> > >>> > >
> > >>> > > wrote:
> > >>> > >
> > >>> > > > Hi Chandni,
> > >>> > > >
> > >>> > > > Following are the issues:
> > >>> > > >
> > >>> > > > 1. FieldInfo, is ultimately a custom object and any user who
> > >>> uses
> > >>> > this
> > >>> > > > operator has to construct an object, populate it and then
> use
> > >>> it. We
> > >>> > > are
> > >>> > > > trying to avoid using any custom object and allow any user
> to
> > >>> use
> > >>> > the
> > >>> > > > operator without writing any extra code; just configuration.
> > >>> > > > 2. In case of update / merge, we need what SQL data types
> that
> > >>> the
> > >>> > > > expression provided by the user would evaluate to. In case
> of
> > >>> insert
> > >>> > > we
> > >>> > > > can
> > >>> > > > go and fetch the data types of the columns directly from DB.
> > >>> > However,
> > >>> > > > the
> > >>> > > > same is not possible for custom expressions; "avg(salary)"
> for
> > >>> > > instance.
> > >>> > > >
> > >>> > > > Thanks.
> > >>> > > >
> > >>> > > > -Bhupesh
> > >>> > > >
> > >>> > > >
> > >>> > > > On Mon, Dec 28, 2015 at 2:57 PM, Chandni Singh <
> > >>> > chandni@datatorrent.com>
> > >>> > > > wrote:
> > >>> > > >
> > >>> > > > > Hi Bhupesh,
> > >>> > > > >
> > >>> > > > > JDBCPojoOutputOperator was written for a demo and therefore
> it
> > >>> was
> > >>> > > marked
> > >>> > > > > Evolving which is why I had mentioned that you should feel
> free
> > >>> to
> > >>> > > modify
> > >>> > > > > it.
> > >>> > > > >
> > >>> > > > > I think an insert query can be as complex as any other query.
> > It
> > >>> uses
> > >>> > > > > FieldInfo because in the app builder it is easy for the user
> to
> > >>> > provide
> > >>> > > > > that instead of JSON String.
> > >>> > > > >
> > >>> > > > > Can you please provide specifics about what it is that you
> find
> > >>> > > difficult
> > >>> > > > > to change/implement for providing update/merge/delete support
> > in
> > >>> > > > > JDBCPojoOutputOperator?
> > >>> > > > >
> > >>> > > > > Chandni
> > >>> > > > >
> > >>> > > > > On Mon, Dec 28, 2015 at 1:09 AM, Bhupesh Chawda <
> > >>> > > bhupesh@datatorrent.com
> > >>> > > > >
> > >>> > > > > wrote:
> > >>> > > > >
> > >>> > > > > > Hi All,
> > >>> > > > > >
> > >>> > > > > > It has been pointed out that adding another class for
> > handling
> > >>> > > update /
> > >>> > > > > > merge queries would not be a good option.
> > >>> > > > > >
> > >>> > > > > > Here are the current implementation details:
> > >>> > > > > >
> > >>> > > > > > - We have an existing class: JdbcPOJOOutputOperator
> which
> > >>> > accepts
> > >>> > > a
> > >>> > > > > list
> > >>> > > > > > of FieldInfo objects. Each element of this list
> indicates
> > >>> the
> > >>> > > > details
> > >>> > > > > > (column name, pojo field expression and datatype) of
> > fields
> > >>> that
> > >>> > > > need
> > >>> > > > > > to be
> > >>> > > > > > inserted. Using this, the operator formulates the insert
> > >>> query
> > >>> > in
> > >>> > > > the
> > >>> > > > > > setup
> > >>> > > > > > method and identifies the sql datatypes of these columns
> > >>> from
> > >>> > the
> > >>> > > > > > database
> > >>> > > > > > using the table name.
> > >>> > > > > >
> > >>> > > > > >
> > >>> > > > > > - Now, coming to the update / merge feature, it is
> > >>> difficult to
> > >>> > > > > > formulate the update / merge query in the operator logic
> > >>> due to
> > >>> > > the
> > >>> > > > > > complex
> > >>> > > > > > structure of these statements. For this reason, we plan
> to
> > >>> take
> > >>> > a
> > >>> > > > > > parametrized SQL query from the user. This may look
> like:
> > >>> > *"update
> > >>> > > > > table
> > >>> > > > > > set x = ?, y = ? where z + w > ? and a == 1;"*. Such
> > >>> statements
> > >>> > > can
> > >>> > > > be
> > >>> > > > > > accepted from the user in addition to a json string
> which
> > >>> > > indicates
> > >>> > > > > the
> > >>> > > > > > details for the parameters: *column name, the pojo
> > >>> expression
> > >>> > and
> > >>> > > > the
> > >>> > > > > > sql data type* of the expression. Note that this
> > >>> information is
> > >>> > > > > similar
> > >>> > > > > > to the FieldInfo object, but is a string which can be
> > >>> configured
> > >>> > > > > easily
> > >>> > > > > > by
> > >>> > > > > > the user. Also note that the data type which is accepted
> > is
> > >>> the
> > >>> > > SQL
> > >>> > > > > data
> > >>> > > > > > type. Using this info we can populate the parametrized
> > >>> query and
> > >>> > > run
> > >>> > > > > it
> > >>> > > > > > based on the incoming POJO.
> > >>> > > > > >
> > >>> > > > > > The second approach is able to handle all kinds of queries
> > >>> (insert
> > >>> > /
> > >>> > > > > update
> > >>> > > > > > / merge / delete). However, since we already have the
> > >>> > > > > > JdbcPOJOOutputOperator, we would like to merge the new
> > >>> > functionality
> > >>> > > > into
> > >>> > > > > > the same class.
> > >>> > > > > >
> > >>> > > > > > Here we have the following options:
> > >>> > > > > >
> > >>> > > > > > 1. Change the existing class (JdbcPOJOOutputOperator) to
> > the
> > >>> > > second
> > >>> > > > > > approach which is more generic and also handles inserts.
> > >>> > > > > > 2. Add the update/ merge functionality to the existing
> > class
> > >>> > > without
> > >>> > > > > > changing the existing functionality. This will have two
> > >>> > different
> > >>> > > > ways
> > >>> > > > > > that
> > >>> > > > > > insert queries may be handled in the operator.
> > >>> > > > > > 3. Add another class which extends from
> > >>> JdbcPOJOOutputOperator
> > >>> > and
> > >>> > > > > have
> > >>> > > > > > the update/merge functionality there. (This is not
> > >>> recommended.)
> > >>> > > > > > 4. Any other approach.
> > >>> > > > > >
> > >>> > > > > > Please suggest.
> > >>> > > > > >
> > >>> > > > > > Thanks.
> > >>> > > > > >
> > >>> > > > > > -Bhupesh.
> > >>> > > > > >
> > >>> > > > > >
> > >>> > > > > > On Mon, Dec 14, 2015 at 11:04 AM, Chandni Singh <
> > >>> > > > chandni@datatorrent.com
> > >>> > > > > >
> > >>> > > > > > wrote:
> > >>> > > > > >
> > >>> > > > > > > No I don't think we are restricting Malhar to just
> abstract
> > >>> > > classes.
> > >>> > > > > > > Whenever they are couple of use cases that we see quite
> > >>> often, we
> > >>> > > add
> > >>> > > > > > > concrete implementations.
> > >>> > > > > > >
> > >>> > > > > > > For eg. FileLineInputOperator which is a concrete
> > >>> implementation
> > >>> > of
> > >>> > > > > > > AbstractFileInputOperator. FSSliceReader is an example as
> > >>> well.
> > >>> > > > > > >
> > >>> > > > > > > In AbstractJdbcOutputOperator case there hasn't been such
> > >>> common
> > >>> > > > > > > insert/update query.
> > >>> > > > > > >
> > >>> > > > > > > Also if you look at the example I provided, it is very
> > >>> simple to
> > >>> > > > > provide
> > >>> > > > > > a
> > >>> > > > > > > concrete implementation.
> > >>> > > > > > >
> > >>> > > > > > > If you would like to change JdbcPOJOOutputOperator to
> work
> > >>> for
> > >>> > > > > > > "UPDATE/MERGE" then please go ahead.
> > >>> > > > > > >
> > >>> > > > > > > Chandni
> > >>> > > > > > >
> > >>> > > > > > > On Sun, Dec 13, 2015 at 8:47 PM, Bhupesh Chawda <
> > >>> > > > > bhupesh@datatorrent.com
> > >>> > > > > > >
> > >>> > > > > > > wrote:
> > >>> > > > > > >
> > >>> > > > > > > > I see. So, just to understand more, do we plan to keep
> > >>> Malhar
> > >>> > > > > > restricted
> > >>> > > > > > > to
> > >>> > > > > > > > the base functionality (as in abstract classes)? And
> put
> > >>> the
> > >>> > > > > > > configuration
> > >>> > > > > > > > aspect / concrete implementations in apps that use
> these
> > >>> > > operators?
> > >>> > > > > > > >
> > >>> > > > > > > > Thanks.
> > >>> > > > > > > > Bhupesh
> > >>> > > > > > > >
> > >>> > > > > > > > On Sat, Dec 12, 2015 at 5:43 AM, Chandni Singh <
> > >>> > > > > > chandni@datatorrent.com>
> > >>> > > > > > > > wrote:
> > >>> > > > > > > >
> > >>> > > > > > > > > Hi,
> > >>> > > > > > > > >
> > >>> > > > > > > > > Here is an example of doing Upsert with JDBC:
> > >>> > > > > > > > >
> > >>> > > > > > > > >
> > >>> > > > > > > >
> > >>> > > > > > >
> > >>> > > > > >
> > >>> > > > >
> > >>> > > >
> > >>> > >
> > >>> >
> > >>>
> >
> https://github.com/chandnisingh/Malhar/blob/examples/apps/jdbc/src/main/java/com/datatorrent/jdbc/JdbcWriter.java
> > >>> > > > > > > > >
> > >>> > > > > > > > > Thanks,
> > >>> > > > > > > > > Chandni
> > >>> > > > > > > > >
> > >>> > > > > > > > > On Fri, Dec 11, 2015 at 11:19 AM, Chandni Singh <
> > >>> > > > > > > chandni@datatorrent.com
> > >>> > > > > > > > >
> > >>> > > > > > > > > wrote:
> > >>> > > > > > > > >
> > >>> > > > > > > > > > The operators are under Malhar/lib/db/jdbc.
> > >>> > > > > > > > > >
> > >>> > > > > > > > > > Here is one of them:
> > >>> > > > > > > > > >
> > >>> > > > > > > > > >
> > >>> > > > > > > > >
> > >>> > > > > > > >
> > >>> > > > > > >
> > >>> > > > > >
> > >>> > > > >
> > >>> > > >
> > >>> > >
> > >>> >
> > >>>
> >
> https://github.com/apache/incubator-apex-malhar/blob/devel-3/library/src/main/java/com/datatorrent/lib/db/jdbc/AbstractJdbcTransactionableOutputOperator.java
> > >>> > > > > > > > > >
> > >>> > > > > > > > > > They work with any kind PreparedStatement - insert
> or
> > >>> > update
> > >>> > > > > > > > > >
> > >>> > > > > > > > > > Chandni
> > >>> > > > > > > > > >
> > >>> > > > > > > > > >
> > >>> > > > > > > > > >
> > >>> > > > > > > > > > On Fri, Dec 11, 2015 at 10:59 AM, Bhupesh Chawda <
> > >>> > > > > > > > > bhupesh@datatorrent.com>
> > >>> > > > > > > > > > wrote:
> > >>> > > > > > > > > >
> > >>> > > > > > > > > >> Hi Chandni,
> > >>> > > > > > > > > >>
> > >>> > > > > > > > > >> I don't see an update query being handled in the
> > >>> operator.
> > >>> > > > Could
> > >>> > > > > > you
> > >>> > > > > > > > > >> please
> > >>> > > > > > > > > >> point me to the appropriate class?
> > >>> > > > > > > > > >> Or did you mean that handling a update query is
> > just a
> > >>> > > matter
> > >>> > > > of
> > >>> > > > > > > > > extending
> > >>> > > > > > > > > >> the class and providing a concrete implementation?
> > >>> > > > > > > > > >>
> > >>> > > > > > > > > >> Thanks.
> > >>> > > > > > > > > >> -Bhupesh
> > >>> > > > > > > > > >>
> > >>> > > > > > > > > >> On Fri, Dec 11, 2015 at 10:42 PM, Chandni Singh <
> > >>> > > > > > > > > chandni@datatorrent.com>
> > >>> > > > > > > > > >> wrote:
> > >>> > > > > > > > > >>
> > >>> > > > > > > > > >> > Hi Bhupesh,
> > >>> > > > > > > > > >> >
> > >>> > > > > > > > > >> > The current abstract JDBC Output Operators in
> > >>> library
> > >>> > are
> > >>> > > > > > generic
> > >>> > > > > > > > and
> > >>> > > > > > > > > >> have
> > >>> > > > > > > > > >> > already been used in multiple POCs and
> > >>> applications. In
> > >>> > > fact
> > >>> > > > > > this
> > >>> > > > > > > > > >> operator
> > >>> > > > > > > > > >> > has matured through customer use cases. It is
> not
> > >>> just
> > >>> > an
> > >>> > > > > insert
> > >>> > > > > > > > > >> operator.
> > >>> > > > > > > > > >> > We have used it to perform update and inserts.
> > >>> > > > > > > > > >> >
> > >>> > > > > > > > > >> > That said, I don't think it is a good idea to
> > >>> introduce
> > >>> > > > input
> > >>> > > > > > > format
> > >>> > > > > > > > > in
> > >>> > > > > > > > > >> > these abstract implementations. It is written
> to
> > >>> handle
> > >>> > > any
> > >>> > > > > > type
> > >>> > > > > > > of
> > >>> > > > > > > > > >> query,
> > >>> > > > > > > > > >> > be it a procedure call (that was an actual
> > customer
> > >>> use
> > >>> > > > case).
> > >>> > > > > > > > > >> >
> > >>> > > > > > > > > >> > Chandni
> > >>> > > > > > > > > >> >
> > >>> > > > > > > > > >> > On Fri, Dec 11, 2015 at 2:50 AM, Bhupesh Chawda
> <
> > >>> > > > > > > > > >> bhupesh@datatorrent.com>
> > >>> > > > > > > > > >> > wrote:
> > >>> > > > > > > > > >> >
> > >>> > > > > > > > > >> > > Hi All,
> > >>> > > > > > > > > >> > >
> > >>> > > > > > > > > >> > > We are planning to proceed with the following
> > >>> approach
> > >>> > > for
> > >>> > > > > > JDBC
> > >>> > > > > > > > > >> *update*
> > >>> > > > > > > > > >> > > operator:
> > >>> > > > > > > > > >> > >
> > >>> > > > > > > > > >> > > - *Update Query Configuration*
> > >>> > > > > > > > > >> > >
> > >>> > > > > > > > > >> > >
> > >>> > > > > > > > > >> > > - Example Update Query: *update tableName
> set
> > >>> a =
> > >>> > ?**
> > >>> > > > > > where b
> > >>> > > > > > > > = ?
> > >>> > > > > > > > > >> and
> > >>> > > > > > > > > >> > c
> > >>> > > > > > > > > >> > > > ?;*
> > >>> > > > > > > > > >> > > - Example JSON input array for parameter
> > >>> > > > instantiations:
> > >>> > > > > > > *[{a,
> > >>> > > > > > > > > >> > > expression, INTEGER}, {b, expression,
> > >>> VARCHAR}, {c,
> > >>> > > > > > > expression,
> > >>> > > > > > > > > >> > DATE}]*
> > >>> > > > > > > > > >> > >
> > >>> > > > > > > > > >> > > We are also planning to change the JDBC Output
> > >>> > Operator
> > >>> > > in
> > >>> > > > > > > Malhar
> > >>> > > > > > > > > >> Library
> > >>> > > > > > > > > >> > > which currently does just insert. We plan to
> > make
> > >>> the
> > >>> > > > input
> > >>> > > > > > > format
> > >>> > > > > > > > > >> > > consistent for both insert and update and
> hence
> > >>> the
> > >>> > > change
> > >>> > > > > to
> > >>> > > > > > > the
> > >>> > > > > > > > > >> current
> > >>> > > > > > > > > >> > > way of configuration using JSON. Following
> would
> > >>> be
> > >>> > the
> > >>> > > > > config
> > >>> > > > > > > for
> > >>> > > > > > > > > >> > inserts:
> > >>> > > > > > > > > >> > >
> > >>> > > > > > > > > >> > > - *Insert Query Configuration*
> > >>> > > > > > > > > >> > >
> > >>> > > > > > > > > >> > >
> > >>> > > > > > > > > >> > > - Example Insert Query: *insert into
> > tableName
> > >>> > values
> > >>> > > > (?,
> > >>> > > > > > ?,
> > >>> > > > > > > > .. ,
> > >>> > > > > > > > > >> ?);*
> > >>> > > > > > > > > >> > > - Example JSON input array for parameter
> > >>> > > > instantiations:
> > >>> > > > > > > *[{a,
> > >>> > > > > > > > > >> > > expression, INTEGER}, {b, expression,
> > >>> VARCHAR}, ..
> > >>> > ,
> > >>> > > > {c,
> > >>> > > > > > > > > >> expression,
> > >>> > > > > > > > > >> > > DATE}]*
> > >>> > > > > > > > > >> > >
> > >>> > > > > > > > > >> > > Please let us know your thoughts.
> > >>> > > > > > > > > >> > >
> > >>> > > > > > > > > >> > > Thanks.
> > >>> > > > > > > > > >> > >
> > >>> > > > > > > > > >> > > -Bhupesh
> > >>> > > > > > > > > >> > >
> > >>> > > > > > > > > >> > >
> > >>> > > > > > > > > >> > >
> > >>> > > > > > > > > >> > > On Wed, Dec 9, 2015 at 6:38 PM, Bhupesh
> Chawda <
> > >>> > > > > > > > > >> bhupesh@datatorrent.com>
> > >>> > > > > > > > > >> > > wrote:
> > >>> > > > > > > > > >> > >
> > >>> > > > > > > > > >> > > > Hi All,
> > >>> > > > > > > > > >> > > >
> > >>> > > > > > > > > >> > > > Would it be a good idea to introduce the
> > update
> > >>> > > > > > functionality
> > >>> > > > > > > to
> > >>> > > > > > > > > the
> > >>> > > > > > > > > >> > JDBC
> > >>> > > > > > > > > >> > > > output operator in Apache Apex Malhar
> library.
> > >>> > > > > > > > > >> > > >
> > >>> > > > > > > > > >> > > > The following are possible approaches:
> > >>> > > > > > > > > >> > > >
> > >>> > > > > > > > > >> > > > 1. Accept a update query from the user
> with
> > >>> place
> > >>> > > > > holders
> > >>> > > > > > > for
> > >>> > > > > > > > > >> > values.
> > >>> > > > > > > > > >> > > > Example: *update tableName set a = ?, b
> = ?
> > >>> > where c
> > >>> > > > = ?
> > >>> > > > > > and
> > >>> > > > > > > > d >
> > >>> > > > > > > > > >> ?*.
> > >>> > > > > > > > > >> > > > Here "?" will be provided by the user as
> > java
> > >>> > > > > expressions
> > >>> > > > > > > > which
> > >>> > > > > > > > > >> will
> > >>> > > > > > > > > >> > > be
> > >>> > > > > > > > > >> > > > evaluated from the incoming tuple.
> > >>> > > > > > > > > >> > > > 2. Another option is to accept in some
> > >>> > > configuration
> > >>> > > > > > format
> > >>> > > > > > > > > >> (json /
> > >>> > > > > > > > > >> > > > xml) the following and formulate the
> query
> > >>> in the
> > >>> > > > > > operator.
> > >>> > > > > > > > > This
> > >>> > > > > > > > > >> can
> > >>> > > > > > > > > >> > > become
> > >>> > > > > > > > > >> > > > arbitrarily complex.
> > >>> > > > > > > > > >> > > > 1. update clause columns
> > >>> > > > > > > > > >> > > > 2. update clause expressions
> > >>> > > > > > > > > >> > > > 3. where clause columns
> > >>> > > > > > > > > >> > > > 4. where clause expressions
> > >>> > > > > > > > > >> > > >
> > >>> > > > > > > > > >> > > > I am thinking about going ahead with 1.
> Please
> > >>> let
> > >>> > me
> > >>> > > > know
> > >>> > > > > > if
> > >>> > > > > > > > any
> > >>> > > > > > > > > >> other
> > >>> > > > > > > > > >> > > > option is possible and whether such a
> > >>> functionality
> > >>> > > > > already
> > >>> > > > > > > > exists
> > >>> > > > > > > > > >> in
> > >>> > > > > > > > > >> > > some
> > >>> > > > > > > > > >> > > > other class.
> > >>> > > > > > > > > >> > > >
> > >>> > > > > > > > > >> > > > Thanks.
> > >>> > > > > > > > > >> > > >
> > >>> > > > > > > > > >> > > > -Bhupesh
> > >>> > > > > > > > > >> > > >
> > >>> > > > > > > > > >> > >
> > >>> > > > > > > > > >> >
> > >>> > > > > > > > > >>
> > >>> > > > > > > > > >
> > >>> > > > > > > > > >
> > >>> > > > > > > > >
> > >>> > > > > > > >
> > >>> > > > > > >
> > >>> > > > > >
> > >>> > > > >
> > >>> > > >
> > >>> > >
> > >>> >
> > >>>
> > >>
> > >>
> > >
> >
>
Re: Changes to JdbcOutputOperator
Posted by Priyanka Gugale <pr...@datatorrent.com>.
+1, this is simplifying operator configuration, we should do same for other
DB operators as well.
-Priyanka
On Thu, Mar 10, 2016 at 5:34 PM, Bhupesh Chawda <bh...@datatorrent.com>
wrote:
> Hi All,
>
> Apart from extending the JDBC Output operator (for update, merge and
> delete), I am planning the following change to the "*insert*"
> functionality:
>
>
> - It was pointed out that - if the incoming POJO has fields which are to
> be inserted into a database table, the user should not have to specify
> any
> kind of mapping between POJO columns and database table column names.
> This
> is possible if the POJO field names are same as the db column names.
>
>
> - Here is what I am planning to do to address this:
> - Have a flag which indicates "*No mapping required. Assume same POJO
> field names as the DB column names.*"
> - If this flag is true, extract DB column names (in addition to the
> types, which is done currently) and create getters from POJO based
> on the
> DB column types.
> - Use these getters to populate the parametrized "*insert*" query.
>
>
> Note - Once this is done, the user would not have to specify any field
> descriptions. Just the DB table name would be sufficient. This would only
> be possible if the DB column names are the same as the field names in the
> POJO.
> Without this change, "*insert*" will be considered as just another DDL
> query like "update" / "delete" / "merge". We accept a parametrized query
> and a mapping from the user for POJO field names to DB column names + DB
> column types.
>
> Thanks.
> Bhupesh
>
>
> On Wed, Dec 30, 2015 at 12:56 PM, Bhupesh Chawda <bh...@datatorrent.com>
> wrote:
>
> > Also, since we are not creating separate operators for insert and
> > update/merge, it seems we don't need an abstract class. We can directly
> > modify JdbcPOJOOutputOperator.
> >
> > -Bhupesh
> >
> > On Wed, Dec 30, 2015 at 11:17 AM, Bhupesh Chawda <
> bhupesh@datatorrent.com>
> > wrote:
> >
> >> Also, a note regarding accepting fieldInfo objects:
> >>
> >> FieldInfo has fields for java type of the column, but not the SQL data
> >> type which is needed to set the parameters in the SQL statement. This
> still
> >> needs to be derived from the database (as in insert).
> >> In more complex scenarios, as mentioned earlier, this may not always be
> >> possible. In this case we have the following options:
> >>
> >> 1. Accept the SQL data types from the user for the parameters ("?")
> >> in a new data structure.
> >> 2. Accept the JSON structure as specified earlier.
> >> 3. Modify FieldInfo to have an additional optional field which
> >> indicates the SQL data type of the parameter ("?")
> >>
> >> I am planning to go ahead with option 3.
> >>
> >> Comments?
> >>
> >> -Bhupesh
> >>
> >>
> >>
> >> On Mon, Dec 28, 2015 at 11:26 PM, Chandni Singh <
> chandni@datatorrent.com>
> >> wrote:
> >>
> >>> Yeah that sounds good.
> >>>
> >>> Chandni
> >>>
> >>> On Mon, Dec 28, 2015 at 2:46 AM, Bhupesh Chawda <
> bhupesh@datatorrent.com
> >>> >
> >>> wrote:
> >>>
> >>> > Thanks Chandni for the comments.
> >>> >
> >>> > Additionally I think, we should do away with constructing the SQL
> >>> query in
> >>> > the operator. This is because it is only possible in case of simple
> >>> insert
> >>> > statements. In case a where clause is needed in the insert statement,
> >>> we
> >>> > cannot construct the SQL easily. If we are accepting a parametrized
> >>> query
> >>> > from the user for update/merge, why not do the same for insert
> >>> statements
> >>> > as well? Then the hierarchy would look like:
> >>> > - AbstractJdbcPOJOOutputOperator (As suggested)
> >>> > -- JdbcPOJOOutputOperator (Takes care of all statements insert,
> update,
> >>> > merge, delete)
> >>> >
> >>> > We don't need a separate operator for inserts and update/merge.
> >>> >
> >>> > Thanks.
> >>> > -Bhupesh
> >>> >
> >>> >
> >>> > On Mon, Dec 28, 2015 at 3:32 PM, Chandni Singh <
> >>> chandni@datatorrent.com>
> >>> > wrote:
> >>> >
> >>> > > 1. FieldInfo, is ultimately a custom object and any user who uses
> >>> this
> >>> > > operator has to construct an object, populate it and then use
> it.
> >>> We
> >>> > are
> >>> > > trying to avoid using any custom object and allow any user to
> use
> >>> the
> >>> > > operator without writing any extra code; just configuration.
> >>> > > FieldInfo is a way to provide configuration in a UI friendly way.
> >>> > Providing
> >>> > > configuration as JSON is not UI friendly.
> >>> > >
> >>> > > 2. In case of update / merge, we need what SQL data types that
> the
> >>> > > expression provided by the user would evaluate to. In case of
> >>> insert
> >>> > we
> >>> > > can
> >>> > > go and fetch the data types of the columns directly from DB.
> >>> However,
> >>> > > the
> >>> > > same is not possible for custom expressions; "avg(salary)" for
> >>> > instance.
> >>> > > Ok so here is where you can make a change.
> >>> > > - JDBCPojoOutput can be renamed to AbstractJDBCPojoOutpuOperator.
> >>> > > - Abstraction is to fetch the type of column.
> >>> > > - Add a concrete JDBCPojoInsertOutput that derives the types of
> >>> columns
> >>> > > directly from DB. Please note that FieldInfo can also provide type
> of
> >>> > > derived column.
> >>> > >
> >>> > >
> >>> > > You mentioned "We are trying to avoid using any custom object and
> >>> allow
> >>> > any
> >>> > > user to use the
> >>> > > operator without writing any extra code".
> >>> > > This I think is specific to your use case. You can create an
> >>> extension of
> >>> > > the above which takes JSON blob and creates FieldInfos from it.
> >>> > >
> >>> > > Chandni
> >>> > >
> >>> > >
> >>> > >
> >>> > >
> >>> > >
> >>> > > On Mon, Dec 28, 2015 at 1:48 AM, Bhupesh Chawda <
> >>> bhupesh@datatorrent.com
> >>> > >
> >>> > > wrote:
> >>> > >
> >>> > > > Hi Chandni,
> >>> > > >
> >>> > > > Following are the issues:
> >>> > > >
> >>> > > > 1. FieldInfo, is ultimately a custom object and any user who
> >>> uses
> >>> > this
> >>> > > > operator has to construct an object, populate it and then use
> >>> it. We
> >>> > > are
> >>> > > > trying to avoid using any custom object and allow any user to
> >>> use
> >>> > the
> >>> > > > operator without writing any extra code; just configuration.
> >>> > > > 2. In case of update / merge, we need what SQL data types that
> >>> the
> >>> > > > expression provided by the user would evaluate to. In case of
> >>> insert
> >>> > > we
> >>> > > > can
> >>> > > > go and fetch the data types of the columns directly from DB.
> >>> > However,
> >>> > > > the
> >>> > > > same is not possible for custom expressions; "avg(salary)" for
> >>> > > instance.
> >>> > > >
> >>> > > > Thanks.
> >>> > > >
> >>> > > > -Bhupesh
> >>> > > >
> >>> > > >
> >>> > > > On Mon, Dec 28, 2015 at 2:57 PM, Chandni Singh <
> >>> > chandni@datatorrent.com>
> >>> > > > wrote:
> >>> > > >
> >>> > > > > Hi Bhupesh,
> >>> > > > >
> >>> > > > > JDBCPojoOutputOperator was written for a demo and therefore it
> >>> was
> >>> > > marked
> >>> > > > > Evolving which is why I had mentioned that you should feel free
> >>> to
> >>> > > modify
> >>> > > > > it.
> >>> > > > >
> >>> > > > > I think an insert query can be as complex as any other query.
> It
> >>> uses
> >>> > > > > FieldInfo because in the app builder it is easy for the user to
> >>> > provide
> >>> > > > > that instead of JSON String.
> >>> > > > >
> >>> > > > > Can you please provide specifics about what it is that you find
> >>> > > difficult
> >>> > > > > to change/implement for providing update/merge/delete support
> in
> >>> > > > > JDBCPojoOutputOperator?
> >>> > > > >
> >>> > > > > Chandni
> >>> > > > >
> >>> > > > > On Mon, Dec 28, 2015 at 1:09 AM, Bhupesh Chawda <
> >>> > > bhupesh@datatorrent.com
> >>> > > > >
> >>> > > > > wrote:
> >>> > > > >
> >>> > > > > > Hi All,
> >>> > > > > >
> >>> > > > > > It has been pointed out that adding another class for
> handling
> >>> > > update /
> >>> > > > > > merge queries would not be a good option.
> >>> > > > > >
> >>> > > > > > Here are the current implementation details:
> >>> > > > > >
> >>> > > > > > - We have an existing class: JdbcPOJOOutputOperator which
> >>> > accepts
> >>> > > a
> >>> > > > > list
> >>> > > > > > of FieldInfo objects. Each element of this list indicates
> >>> the
> >>> > > > details
> >>> > > > > > (column name, pojo field expression and datatype) of
> fields
> >>> that
> >>> > > > need
> >>> > > > > > to be
> >>> > > > > > inserted. Using this, the operator formulates the insert
> >>> query
> >>> > in
> >>> > > > the
> >>> > > > > > setup
> >>> > > > > > method and identifies the sql datatypes of these columns
> >>> from
> >>> > the
> >>> > > > > > database
> >>> > > > > > using the table name.
> >>> > > > > >
> >>> > > > > >
> >>> > > > > > - Now, coming to the update / merge feature, it is
> >>> difficult to
> >>> > > > > > formulate the update / merge query in the operator logic
> >>> due to
> >>> > > the
> >>> > > > > > complex
> >>> > > > > > structure of these statements. For this reason, we plan to
> >>> take
> >>> > a
> >>> > > > > > parametrized SQL query from the user. This may look like:
> >>> > *"update
> >>> > > > > table
> >>> > > > > > set x = ?, y = ? where z + w > ? and a == 1;"*. Such
> >>> statements
> >>> > > can
> >>> > > > be
> >>> > > > > > accepted from the user in addition to a json string which
> >>> > > indicates
> >>> > > > > the
> >>> > > > > > details for the parameters: *column name, the pojo
> >>> expression
> >>> > and
> >>> > > > the
> >>> > > > > > sql data type* of the expression. Note that this
> >>> information is
> >>> > > > > similar
> >>> > > > > > to the FieldInfo object, but is a string which can be
> >>> configured
> >>> > > > > easily
> >>> > > > > > by
> >>> > > > > > the user. Also note that the data type which is accepted
> is
> >>> the
> >>> > > SQL
> >>> > > > > data
> >>> > > > > > type. Using this info we can populate the parametrized
> >>> query and
> >>> > > run
> >>> > > > > it
> >>> > > > > > based on the incoming POJO.
> >>> > > > > >
> >>> > > > > > The second approach is able to handle all kinds of queries
> >>> (insert
> >>> > /
> >>> > > > > update
> >>> > > > > > / merge / delete). However, since we already have the
> >>> > > > > > JdbcPOJOOutputOperator, we would like to merge the new
> >>> > functionality
> >>> > > > into
> >>> > > > > > the same class.
> >>> > > > > >
> >>> > > > > > Here we have the following options:
> >>> > > > > >
> >>> > > > > > 1. Change the existing class (JdbcPOJOOutputOperator) to
> the
> >>> > > second
> >>> > > > > > approach which is more generic and also handles inserts.
> >>> > > > > > 2. Add the update/ merge functionality to the existing
> class
> >>> > > without
> >>> > > > > > changing the existing functionality. This will have two
> >>> > different
> >>> > > > ways
> >>> > > > > > that
> >>> > > > > > insert queries may be handled in the operator.
> >>> > > > > > 3. Add another class which extends from
> >>> JdbcPOJOOutputOperator
> >>> > and
> >>> > > > > have
> >>> > > > > > the update/merge functionality there. (This is not
> >>> recommended.)
> >>> > > > > > 4. Any other approach.
> >>> > > > > >
> >>> > > > > > Please suggest.
> >>> > > > > >
> >>> > > > > > Thanks.
> >>> > > > > >
> >>> > > > > > -Bhupesh.
> >>> > > > > >
> >>> > > > > >
> >>> > > > > > On Mon, Dec 14, 2015 at 11:04 AM, Chandni Singh <
> >>> > > > chandni@datatorrent.com
> >>> > > > > >
> >>> > > > > > wrote:
> >>> > > > > >
> >>> > > > > > > No I don't think we are restricting Malhar to just abstract
> >>> > > classes.
> >>> > > > > > > Whenever they are couple of use cases that we see quite
> >>> often, we
> >>> > > add
> >>> > > > > > > concrete implementations.
> >>> > > > > > >
> >>> > > > > > > For eg. FileLineInputOperator which is a concrete
> >>> implementation
> >>> > of
> >>> > > > > > > AbstractFileInputOperator. FSSliceReader is an example as
> >>> well.
> >>> > > > > > >
> >>> > > > > > > In AbstractJdbcOutputOperator case there hasn't been such
> >>> common
> >>> > > > > > > insert/update query.
> >>> > > > > > >
> >>> > > > > > > Also if you look at the example I provided, it is very
> >>> simple to
> >>> > > > > provide
> >>> > > > > > a
> >>> > > > > > > concrete implementation.
> >>> > > > > > >
> >>> > > > > > > If you would like to change JdbcPOJOOutputOperator to work
> >>> for
> >>> > > > > > > "UPDATE/MERGE" then please go ahead.
> >>> > > > > > >
> >>> > > > > > > Chandni
> >>> > > > > > >
> >>> > > > > > > On Sun, Dec 13, 2015 at 8:47 PM, Bhupesh Chawda <
> >>> > > > > bhupesh@datatorrent.com
> >>> > > > > > >
> >>> > > > > > > wrote:
> >>> > > > > > >
> >>> > > > > > > > I see. So, just to understand more, do we plan to keep
> >>> Malhar
> >>> > > > > > restricted
> >>> > > > > > > to
> >>> > > > > > > > the base functionality (as in abstract classes)? And put
> >>> the
> >>> > > > > > > configuration
> >>> > > > > > > > aspect / concrete implementations in apps that use these
> >>> > > operators?
> >>> > > > > > > >
> >>> > > > > > > > Thanks.
> >>> > > > > > > > Bhupesh
> >>> > > > > > > >
> >>> > > > > > > > On Sat, Dec 12, 2015 at 5:43 AM, Chandni Singh <
> >>> > > > > > chandni@datatorrent.com>
> >>> > > > > > > > wrote:
> >>> > > > > > > >
> >>> > > > > > > > > Hi,
> >>> > > > > > > > >
> >>> > > > > > > > > Here is an example of doing Upsert with JDBC:
> >>> > > > > > > > >
> >>> > > > > > > > >
> >>> > > > > > > >
> >>> > > > > > >
> >>> > > > > >
> >>> > > > >
> >>> > > >
> >>> > >
> >>> >
> >>>
> https://github.com/chandnisingh/Malhar/blob/examples/apps/jdbc/src/main/java/com/datatorrent/jdbc/JdbcWriter.java
> >>> > > > > > > > >
> >>> > > > > > > > > Thanks,
> >>> > > > > > > > > Chandni
> >>> > > > > > > > >
> >>> > > > > > > > > On Fri, Dec 11, 2015 at 11:19 AM, Chandni Singh <
> >>> > > > > > > chandni@datatorrent.com
> >>> > > > > > > > >
> >>> > > > > > > > > wrote:
> >>> > > > > > > > >
> >>> > > > > > > > > > The operators are under Malhar/lib/db/jdbc.
> >>> > > > > > > > > >
> >>> > > > > > > > > > Here is one of them:
> >>> > > > > > > > > >
> >>> > > > > > > > > >
> >>> > > > > > > > >
> >>> > > > > > > >
> >>> > > > > > >
> >>> > > > > >
> >>> > > > >
> >>> > > >
> >>> > >
> >>> >
> >>>
> https://github.com/apache/incubator-apex-malhar/blob/devel-3/library/src/main/java/com/datatorrent/lib/db/jdbc/AbstractJdbcTransactionableOutputOperator.java
> >>> > > > > > > > > >
> >>> > > > > > > > > > They work with any kind PreparedStatement - insert or
> >>> > update
> >>> > > > > > > > > >
> >>> > > > > > > > > > Chandni
> >>> > > > > > > > > >
> >>> > > > > > > > > >
> >>> > > > > > > > > >
> >>> > > > > > > > > > On Fri, Dec 11, 2015 at 10:59 AM, Bhupesh Chawda <
> >>> > > > > > > > > bhupesh@datatorrent.com>
> >>> > > > > > > > > > wrote:
> >>> > > > > > > > > >
> >>> > > > > > > > > >> Hi Chandni,
> >>> > > > > > > > > >>
> >>> > > > > > > > > >> I don't see an update query being handled in the
> >>> operator.
> >>> > > > Could
> >>> > > > > > you
> >>> > > > > > > > > >> please
> >>> > > > > > > > > >> point me to the appropriate class?
> >>> > > > > > > > > >> Or did you mean that handling a update query is
> just a
> >>> > > matter
> >>> > > > of
> >>> > > > > > > > > extending
> >>> > > > > > > > > >> the class and providing a concrete implementation?
> >>> > > > > > > > > >>
> >>> > > > > > > > > >> Thanks.
> >>> > > > > > > > > >> -Bhupesh
> >>> > > > > > > > > >>
> >>> > > > > > > > > >> On Fri, Dec 11, 2015 at 10:42 PM, Chandni Singh <
> >>> > > > > > > > > chandni@datatorrent.com>
> >>> > > > > > > > > >> wrote:
> >>> > > > > > > > > >>
> >>> > > > > > > > > >> > Hi Bhupesh,
> >>> > > > > > > > > >> >
> >>> > > > > > > > > >> > The current abstract JDBC Output Operators in
> >>> library
> >>> > are
> >>> > > > > > generic
> >>> > > > > > > > and
> >>> > > > > > > > > >> have
> >>> > > > > > > > > >> > already been used in multiple POCs and
> >>> applications. In
> >>> > > fact
> >>> > > > > > this
> >>> > > > > > > > > >> operator
> >>> > > > > > > > > >> > has matured through customer use cases. It is not
> >>> just
> >>> > an
> >>> > > > > insert
> >>> > > > > > > > > >> operator.
> >>> > > > > > > > > >> > We have used it to perform update and inserts.
> >>> > > > > > > > > >> >
> >>> > > > > > > > > >> > That said, I don't think it is a good idea to
> >>> introduce
> >>> > > > input
> >>> > > > > > > format
> >>> > > > > > > > > in
> >>> > > > > > > > > >> > these abstract implementations. It is written to
> >>> handle
> >>> > > any
> >>> > > > > > type
> >>> > > > > > > of
> >>> > > > > > > > > >> query,
> >>> > > > > > > > > >> > be it a procedure call (that was an actual
> customer
> >>> use
> >>> > > > case).
> >>> > > > > > > > > >> >
> >>> > > > > > > > > >> > Chandni
> >>> > > > > > > > > >> >
> >>> > > > > > > > > >> > On Fri, Dec 11, 2015 at 2:50 AM, Bhupesh Chawda <
> >>> > > > > > > > > >> bhupesh@datatorrent.com>
> >>> > > > > > > > > >> > wrote:
> >>> > > > > > > > > >> >
> >>> > > > > > > > > >> > > Hi All,
> >>> > > > > > > > > >> > >
> >>> > > > > > > > > >> > > We are planning to proceed with the following
> >>> approach
> >>> > > for
> >>> > > > > > JDBC
> >>> > > > > > > > > >> *update*
> >>> > > > > > > > > >> > > operator:
> >>> > > > > > > > > >> > >
> >>> > > > > > > > > >> > > - *Update Query Configuration*
> >>> > > > > > > > > >> > >
> >>> > > > > > > > > >> > >
> >>> > > > > > > > > >> > > - Example Update Query: *update tableName set
> >>> a =
> >>> > ?**
> >>> > > > > > where b
> >>> > > > > > > > = ?
> >>> > > > > > > > > >> and
> >>> > > > > > > > > >> > c
> >>> > > > > > > > > >> > > > ?;*
> >>> > > > > > > > > >> > > - Example JSON input array for parameter
> >>> > > > instantiations:
> >>> > > > > > > *[{a,
> >>> > > > > > > > > >> > > expression, INTEGER}, {b, expression,
> >>> VARCHAR}, {c,
> >>> > > > > > > expression,
> >>> > > > > > > > > >> > DATE}]*
> >>> > > > > > > > > >> > >
> >>> > > > > > > > > >> > > We are also planning to change the JDBC Output
> >>> > Operator
> >>> > > in
> >>> > > > > > > Malhar
> >>> > > > > > > > > >> Library
> >>> > > > > > > > > >> > > which currently does just insert. We plan to
> make
> >>> the
> >>> > > > input
> >>> > > > > > > format
> >>> > > > > > > > > >> > > consistent for both insert and update and hence
> >>> the
> >>> > > change
> >>> > > > > to
> >>> > > > > > > the
> >>> > > > > > > > > >> current
> >>> > > > > > > > > >> > > way of configuration using JSON. Following would
> >>> be
> >>> > the
> >>> > > > > config
> >>> > > > > > > for
> >>> > > > > > > > > >> > inserts:
> >>> > > > > > > > > >> > >
> >>> > > > > > > > > >> > > - *Insert Query Configuration*
> >>> > > > > > > > > >> > >
> >>> > > > > > > > > >> > >
> >>> > > > > > > > > >> > > - Example Insert Query: *insert into
> tableName
> >>> > values
> >>> > > > (?,
> >>> > > > > > ?,
> >>> > > > > > > > .. ,
> >>> > > > > > > > > >> ?);*
> >>> > > > > > > > > >> > > - Example JSON input array for parameter
> >>> > > > instantiations:
> >>> > > > > > > *[{a,
> >>> > > > > > > > > >> > > expression, INTEGER}, {b, expression,
> >>> VARCHAR}, ..
> >>> > ,
> >>> > > > {c,
> >>> > > > > > > > > >> expression,
> >>> > > > > > > > > >> > > DATE}]*
> >>> > > > > > > > > >> > >
> >>> > > > > > > > > >> > > Please let us know your thoughts.
> >>> > > > > > > > > >> > >
> >>> > > > > > > > > >> > > Thanks.
> >>> > > > > > > > > >> > >
> >>> > > > > > > > > >> > > -Bhupesh
> >>> > > > > > > > > >> > >
> >>> > > > > > > > > >> > >
> >>> > > > > > > > > >> > >
> >>> > > > > > > > > >> > > On Wed, Dec 9, 2015 at 6:38 PM, Bhupesh Chawda <
> >>> > > > > > > > > >> bhupesh@datatorrent.com>
> >>> > > > > > > > > >> > > wrote:
> >>> > > > > > > > > >> > >
> >>> > > > > > > > > >> > > > Hi All,
> >>> > > > > > > > > >> > > >
> >>> > > > > > > > > >> > > > Would it be a good idea to introduce the
> update
> >>> > > > > > functionality
> >>> > > > > > > to
> >>> > > > > > > > > the
> >>> > > > > > > > > >> > JDBC
> >>> > > > > > > > > >> > > > output operator in Apache Apex Malhar library.
> >>> > > > > > > > > >> > > >
> >>> > > > > > > > > >> > > > The following are possible approaches:
> >>> > > > > > > > > >> > > >
> >>> > > > > > > > > >> > > > 1. Accept a update query from the user with
> >>> place
> >>> > > > > holders
> >>> > > > > > > for
> >>> > > > > > > > > >> > values.
> >>> > > > > > > > > >> > > > Example: *update tableName set a = ?, b = ?
> >>> > where c
> >>> > > > = ?
> >>> > > > > > and
> >>> > > > > > > > d >
> >>> > > > > > > > > >> ?*.
> >>> > > > > > > > > >> > > > Here "?" will be provided by the user as
> java
> >>> > > > > expressions
> >>> > > > > > > > which
> >>> > > > > > > > > >> will
> >>> > > > > > > > > >> > > be
> >>> > > > > > > > > >> > > > evaluated from the incoming tuple.
> >>> > > > > > > > > >> > > > 2. Another option is to accept in some
> >>> > > configuration
> >>> > > > > > format
> >>> > > > > > > > > >> (json /
> >>> > > > > > > > > >> > > > xml) the following and formulate the query
> >>> in the
> >>> > > > > > operator.
> >>> > > > > > > > > This
> >>> > > > > > > > > >> can
> >>> > > > > > > > > >> > > become
> >>> > > > > > > > > >> > > > arbitrarily complex.
> >>> > > > > > > > > >> > > > 1. update clause columns
> >>> > > > > > > > > >> > > > 2. update clause expressions
> >>> > > > > > > > > >> > > > 3. where clause columns
> >>> > > > > > > > > >> > > > 4. where clause expressions
> >>> > > > > > > > > >> > > >
> >>> > > > > > > > > >> > > > I am thinking about going ahead with 1. Please
> >>> let
> >>> > me
> >>> > > > know
> >>> > > > > > if
> >>> > > > > > > > any
> >>> > > > > > > > > >> other
> >>> > > > > > > > > >> > > > option is possible and whether such a
> >>> functionality
> >>> > > > > already
> >>> > > > > > > > exists
> >>> > > > > > > > > >> in
> >>> > > > > > > > > >> > > some
> >>> > > > > > > > > >> > > > other class.
> >>> > > > > > > > > >> > > >
> >>> > > > > > > > > >> > > > Thanks.
> >>> > > > > > > > > >> > > >
> >>> > > > > > > > > >> > > > -Bhupesh
> >>> > > > > > > > > >> > > >
> >>> > > > > > > > > >> > >
> >>> > > > > > > > > >> >
> >>> > > > > > > > > >>
> >>> > > > > > > > > >
> >>> > > > > > > > > >
> >>> > > > > > > > >
> >>> > > > > > > >
> >>> > > > > > >
> >>> > > > > >
> >>> > > > >
> >>> > > >
> >>> > >
> >>> >
> >>>
> >>
> >>
> >
>