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Posted to user@cassandra.apache.org by Jens Hartung <ho...@gmx.de> on 2011/08/03 03:58:22 UTC
CQL: How to escape single quotes?
Hi all,
first, i'm new to Cassandra. I'm use Cassandra 0.8.2 with CQL JDBC Driver Version 1.0.3.
My problem is, that I have to insert a large amount of weather data to Cassandra via JAVA. Some of the weather station have single quotes in their name.
When I insert them directly via a Statement, i got a SQLException: mismatched character '<EOF>' expecting '''.
Code is something like this:
Statement stmt = connection.createStatement();
stmt.execute("INSERT INTO station (KEY, name, ...) VALUES ('" + key + "', '" + name "', ... + ");");
Therefore I tried to escape the single quotes via following method:
public String escapeString(String string) {
StringBuilder result = new StringBuilder();
StringCharacterIterator it = new StringCharacterIterator(string);
char c = it.current();
while (c != CharacterIterator.DONE) {
if (c == '\'') {
result.append('\\');
result.append('\'');
} else {
result.append(c);
}
c = it.next();
}
return result.toString();
}
But this also doesn't work.
Is there a way, to insert Strings with single quotes to Cassandra via CQL?
Thanks,
Jens
--
NEU: FreePhone - 0ct/min Handyspartarif mit Geld-zurück-Garantie!
Jetzt informieren: http://www.gmx.net/de/go/freephone
Re: CQL: No indexed column error when < or <= in WHERE clause
Posted by Jens Hartung <ho...@gmx.de>.
Thanks for all the explanations.
It's odd, that pure range queries are not supported at this time. But I think I'll find a solution for my problem.
Greetings
-------- Original-Nachricht --------
> Datum: Sun, 14 Aug 2011 07:09:55 -0700
> Von: Jason Rutherglen <ja...@gmail.com>
> An: user@cassandra.apache.org
> Betreff: Re: CQL: No indexed column error when < or <= in WHERE clause
> This will be fully solved with CASSANDRA-2915 which will use Lucene as
> a the secondary index type implementation. Lucene has extremely fast
> range queries built in.
>
> On Sun, Aug 14, 2011 at 6:38 AM, Sal Fuentes <fu...@gmail.com> wrote:
> > The important piece that is mentioned in Jonathan's link is this:
> > "One consequence of the KEYS index type being more like a hash index
> than a
> > btree is shown here: even though birth_date is indexed, Cassandra
> couldn’t
> > perform the range query “> 1970″ against it."
> > hash index vs a btree index. Basically what this means is that these
> > secondary indexes do not currently support queries of the type greater
> than,
> > less than on a single column.
> > However, Cassandra will allow you to submit these types of queries when
> you
> > have multiple indexed columns; even though it may not be very efficient.
> > "We can perform the range query now that the state column is also
> indexed,
> > so Cassandra can use the state predicate as the primary and filter on
> the
> > other with a nested loop."
> > [default@demo] get users where birth_date = 1973;
> > -------------------
> > RowKey: prothfuss
> > => (column=birth_date, value=1973, timestamp=1313327531411000)
> > => (column=full_name, value=Patrick Rothfuss,
> timestamp=1313327526515000)
> > 1 Row Returned.
> > [default@demo] get users where birth_date > 1972;
> > No indexed columns present in index clause with operator EQ
> > [default@demo] get users where birth_date < 1974;
> > No indexed columns present in index clause with operator EQ
> > [default@demo] get users where birth_date >= 1973;
> > No indexed columns present in index clause with operator EQ
> >
> > On Sun, Aug 14, 2011 at 6:11 AM, Martin von Zweigbergk
> > <ma...@gmail.com> wrote:
> >>
> >> Hi Jens,
> >>
> >> I have never used CQL myself and I have barely used Cassandra, but I
> >> think I've seen it mentioned before on this list that you need to use
> >> compare for equality on at least one column (as indicated by "No
> >> indexed columns present in by-columns clause with "equals" operator").
> >> The lookup will then be done based on that column and additional
> >> filtering (such as for "less than") will be done on the result of the
> >> first lookup, which can potentially be a large data set. You might
> >> also want to redesign your data model to allow for a more efficient
> >> lookup.
> >>
> >> Hope that helps (despite my lack of knowledge on the subject)
> >> Martin
> >>
> >> On Sun, Aug 14, 2011 at 8:53 AM, Jens Hartung <ho...@gmx.de> wrote:
> >> > I had indexed the number column in station column family. Do I also
> have
> >> > to index another column?
> >> >
> >> > What I'm wondering, when I type "get station where number = 8210;"
> all
> >> > works fine, but when I type "get station where number < 8210;" I'll
> get
> >> > mentioned exception.
> >> >
> >> > Is there something, that I misunderstand?
> >> >
> >> > -------- Original-Nachricht --------
> >> >> Datum: Sat, 13 Aug 2011 18:14:05 -0700
> >> >> Von: Jonathan Ellis <jb...@gmail.com>
> >> >> An: user@cassandra.apache.org
> >> >> Betreff: Re: CQL: No indexed column error when < or <= in WHERE
> clause
> >> >
> >> >> This is covered in
> >> >>
> >> >>
> http://www.datastax.com/dev/blog/whats-new-cassandra-07-secondary-indexes
> >> >>
> >> >> On Sat, Aug 13, 2011 at 2:49 PM, Jens Hartung <ho...@gmx.de> wrote:
> >> >> > Hi together,
> >> >> >
> >> >> > first, I'm using Cassandra Version 0.8.4 and access it via CQL
> 1.0.3.
> >> >> >
> >> >> > When I select data from Cassandra with = in WHERE clause,
> everything
> >> >> works fine, but when using <= or < in WHERE clause, I always get
> >> >> following
> >> >> Exception:
> >> >> >
> >> >> > java.sql.SQLException: No indexed columns present in by-columns
> >> >> > clause
> >> >> with "equals" operator
> >> >> > at
> >> >>
> >> >>
> org.apache.cassandra.cql.jdbc.CassandraStatement.executeQuery(CassandraStatement.java:242)
> >> >> > at
> >> >>
> >> >>
> columnfamily.queries.CassandraQueries.singleColumnSelect(CassandraQueries.java:147)
> >> >> > ...
> >> >> >
> >> >> > My select-statement: "SELECT number FROM station WHERE number <=
> >> >> > 8210;"
> >> >> >
> >> >> > Output of describe keyspace (within cli):
> >> >> > ColumnFamily: station
> >> >> > Key Validation Class:
> org.apache.cassandra.db.marshal.UTF8Type
> >> >> > Default column value validator:
> >> >> org.apache.cassandra.db.marshal.UTF8Type
> >> >> > Columns sorted by:
> org.apache.cassandra.db.marshal.UTF8Type
> >> >> > Row cache size / save period in seconds: 0.0/0
> >> >> > Key cache size / save period in seconds: 200000.0/14400
> >> >> > Memtable thresholds: 0.2109375/1440/45 (millions of
> >> >> ops/minutes/MB)
> >> >> > GC grace seconds: 864000
> >> >> > Compaction min/max thresholds: 4/32
> >> >> > Read repair chance: 1.0
> >> >> > Replicate on write: true
> >> >> > Built indexes: [station.station_number_idx]
> >> >> > Column Metadata:
> >> >> > [...]
> >> >> > Column Name: number
> >> >> > Validation Class:
> org.apache.cassandra.db.marshal.LongType
> >> >> > Index Name: station_number_idx
> >> >> > Index Type: KEYS
> >> >> > [...]
> >> >> >
> >> >> > Are the <, <=, >=, > operators not supported at this time?
> >> >> >
> >> >> > Greetings
> >> >> > Jens
> >> >> > --
> >> >> > NEU: FreePhone - 0ct/min Handyspartarif mit Geld-zurück-Garantie!
> >> >> > Jetzt informieren: http://www.gmx.net/de/go/freephone
> >> >> >
> >> >>
> >> >>
> >> >>
> >> >> --
> >> >> Jonathan Ellis
> >> >> Project Chair, Apache Cassandra
> >> >> co-founder of DataStax, the source for professional Cassandra
> support
> >> >> http://www.datastax.com
> >> >
> >> > --
> >> > NEU: FreePhone - 0ct/min Handyspartarif mit Geld-zurück-Garantie!
> >> > Jetzt informieren: http://www.gmx.net/de/go/freephone
> >> >
> >
> >
> >
> > --
> > Salvador Fuentes Jr.
> >
--
Empfehlen Sie GMX DSL Ihren Freunden und Bekannten und wir
belohnen Sie mit bis zu 50,- Euro! https://freundschaftswerbung.gmx.de
Re: CQL: No indexed column error when < or <= in WHERE clause
Posted by Jason Rutherglen <ja...@gmail.com>.
This will be fully solved with CASSANDRA-2915 which will use Lucene as
a the secondary index type implementation. Lucene has extremely fast
range queries built in.
On Sun, Aug 14, 2011 at 6:38 AM, Sal Fuentes <fu...@gmail.com> wrote:
> The important piece that is mentioned in Jonathan's link is this:
> "One consequence of the KEYS index type being more like a hash index than a
> btree is shown here: even though birth_date is indexed, Cassandra couldn’t
> perform the range query “> 1970″ against it."
> hash index vs a btree index. Basically what this means is that these
> secondary indexes do not currently support queries of the type greater than,
> less than on a single column.
> However, Cassandra will allow you to submit these types of queries when you
> have multiple indexed columns; even though it may not be very efficient.
> "We can perform the range query now that the state column is also indexed,
> so Cassandra can use the state predicate as the primary and filter on the
> other with a nested loop."
> [default@demo] get users where birth_date = 1973;
> -------------------
> RowKey: prothfuss
> => (column=birth_date, value=1973, timestamp=1313327531411000)
> => (column=full_name, value=Patrick Rothfuss, timestamp=1313327526515000)
> 1 Row Returned.
> [default@demo] get users where birth_date > 1972;
> No indexed columns present in index clause with operator EQ
> [default@demo] get users where birth_date < 1974;
> No indexed columns present in index clause with operator EQ
> [default@demo] get users where birth_date >= 1973;
> No indexed columns present in index clause with operator EQ
>
> On Sun, Aug 14, 2011 at 6:11 AM, Martin von Zweigbergk
> <ma...@gmail.com> wrote:
>>
>> Hi Jens,
>>
>> I have never used CQL myself and I have barely used Cassandra, but I
>> think I've seen it mentioned before on this list that you need to use
>> compare for equality on at least one column (as indicated by "No
>> indexed columns present in by-columns clause with "equals" operator").
>> The lookup will then be done based on that column and additional
>> filtering (such as for "less than") will be done on the result of the
>> first lookup, which can potentially be a large data set. You might
>> also want to redesign your data model to allow for a more efficient
>> lookup.
>>
>> Hope that helps (despite my lack of knowledge on the subject)
>> Martin
>>
>> On Sun, Aug 14, 2011 at 8:53 AM, Jens Hartung <ho...@gmx.de> wrote:
>> > I had indexed the number column in station column family. Do I also have
>> > to index another column?
>> >
>> > What I'm wondering, when I type "get station where number = 8210;" all
>> > works fine, but when I type "get station where number < 8210;" I'll get
>> > mentioned exception.
>> >
>> > Is there something, that I misunderstand?
>> >
>> > -------- Original-Nachricht --------
>> >> Datum: Sat, 13 Aug 2011 18:14:05 -0700
>> >> Von: Jonathan Ellis <jb...@gmail.com>
>> >> An: user@cassandra.apache.org
>> >> Betreff: Re: CQL: No indexed column error when < or <= in WHERE clause
>> >
>> >> This is covered in
>> >>
>> >> http://www.datastax.com/dev/blog/whats-new-cassandra-07-secondary-indexes
>> >>
>> >> On Sat, Aug 13, 2011 at 2:49 PM, Jens Hartung <ho...@gmx.de> wrote:
>> >> > Hi together,
>> >> >
>> >> > first, I'm using Cassandra Version 0.8.4 and access it via CQL 1.0.3.
>> >> >
>> >> > When I select data from Cassandra with = in WHERE clause, everything
>> >> works fine, but when using <= or < in WHERE clause, I always get
>> >> following
>> >> Exception:
>> >> >
>> >> > java.sql.SQLException: No indexed columns present in by-columns
>> >> > clause
>> >> with "equals" operator
>> >> > at
>> >>
>> >> org.apache.cassandra.cql.jdbc.CassandraStatement.executeQuery(CassandraStatement.java:242)
>> >> > at
>> >>
>> >> columnfamily.queries.CassandraQueries.singleColumnSelect(CassandraQueries.java:147)
>> >> > ...
>> >> >
>> >> > My select-statement: "SELECT number FROM station WHERE number <=
>> >> > 8210;"
>> >> >
>> >> > Output of describe keyspace (within cli):
>> >> > ColumnFamily: station
>> >> > Key Validation Class: org.apache.cassandra.db.marshal.UTF8Type
>> >> > Default column value validator:
>> >> org.apache.cassandra.db.marshal.UTF8Type
>> >> > Columns sorted by: org.apache.cassandra.db.marshal.UTF8Type
>> >> > Row cache size / save period in seconds: 0.0/0
>> >> > Key cache size / save period in seconds: 200000.0/14400
>> >> > Memtable thresholds: 0.2109375/1440/45 (millions of
>> >> ops/minutes/MB)
>> >> > GC grace seconds: 864000
>> >> > Compaction min/max thresholds: 4/32
>> >> > Read repair chance: 1.0
>> >> > Replicate on write: true
>> >> > Built indexes: [station.station_number_idx]
>> >> > Column Metadata:
>> >> > [...]
>> >> > Column Name: number
>> >> > Validation Class: org.apache.cassandra.db.marshal.LongType
>> >> > Index Name: station_number_idx
>> >> > Index Type: KEYS
>> >> > [...]
>> >> >
>> >> > Are the <, <=, >=, > operators not supported at this time?
>> >> >
>> >> > Greetings
>> >> > Jens
>> >> > --
>> >> > NEU: FreePhone - 0ct/min Handyspartarif mit Geld-zurück-Garantie!
>> >> > Jetzt informieren: http://www.gmx.net/de/go/freephone
>> >> >
>> >>
>> >>
>> >>
>> >> --
>> >> Jonathan Ellis
>> >> Project Chair, Apache Cassandra
>> >> co-founder of DataStax, the source for professional Cassandra support
>> >> http://www.datastax.com
>> >
>> > --
>> > NEU: FreePhone - 0ct/min Handyspartarif mit Geld-zurück-Garantie!
>> > Jetzt informieren: http://www.gmx.net/de/go/freephone
>> >
>
>
>
> --
> Salvador Fuentes Jr.
>
Re: CQL: No indexed column error when < or <= in WHERE clause
Posted by Sal Fuentes <fu...@gmail.com>.
The important piece that is mentioned in Jonathan's link is this:
"One consequence of the KEYS index type being more like a hash index than a
btree is shown here: even though birth_date is indexed, Cassandra couldn’t
perform the range query “> 1970″ against it."
hash index vs a btree index. Basically what this means is that these
secondary indexes do not currently support queries of the type greater than,
less than on a single column.
However, Cassandra will allow you to submit these types of queries when you
have multiple indexed columns; even though it may not be very efficient.
"We can perform the range query now that the state column is also indexed,
so Cassandra can use the state predicate as the primary and filter on the
other with a nested loop."
[default@demo] get users where birth_date = 1973;
-------------------
RowKey: prothfuss
=> (column=birth_date, value=1973, timestamp=1313327531411000)
=> (column=full_name, value=Patrick Rothfuss, timestamp=1313327526515000)
1 Row Returned.
[default@demo] get users where birth_date > 1972;
No indexed columns present in index clause with operator EQ
[default@demo] get users where birth_date < 1974;
No indexed columns present in index clause with operator EQ
[default@demo] get users where birth_date >= 1973;
No indexed columns present in index clause with operator EQ
On Sun, Aug 14, 2011 at 6:11 AM, Martin von Zweigbergk <
martin.von.zweigbergk@gmail.com> wrote:
> Hi Jens,
>
> I have never used CQL myself and I have barely used Cassandra, but I
> think I've seen it mentioned before on this list that you need to use
> compare for equality on at least one column (as indicated by "No
> indexed columns present in by-columns clause with "equals" operator").
> The lookup will then be done based on that column and additional
> filtering (such as for "less than") will be done on the result of the
> first lookup, which can potentially be a large data set. You might
> also want to redesign your data model to allow for a more efficient
> lookup.
>
> Hope that helps (despite my lack of knowledge on the subject)
> Martin
>
> On Sun, Aug 14, 2011 at 8:53 AM, Jens Hartung <ho...@gmx.de> wrote:
> > I had indexed the number column in station column family. Do I also have
> to index another column?
> >
> > What I'm wondering, when I type "get station where number = 8210;" all
> works fine, but when I type "get station where number < 8210;" I'll get
> mentioned exception.
> >
> > Is there something, that I misunderstand?
> >
> > -------- Original-Nachricht --------
> >> Datum: Sat, 13 Aug 2011 18:14:05 -0700
> >> Von: Jonathan Ellis <jb...@gmail.com>
> >> An: user@cassandra.apache.org
> >> Betreff: Re: CQL: No indexed column error when < or <= in WHERE clause
> >
> >> This is covered in
> >>
> http://www.datastax.com/dev/blog/whats-new-cassandra-07-secondary-indexes
> >>
> >> On Sat, Aug 13, 2011 at 2:49 PM, Jens Hartung <ho...@gmx.de> wrote:
> >> > Hi together,
> >> >
> >> > first, I'm using Cassandra Version 0.8.4 and access it via CQL 1.0.3.
> >> >
> >> > When I select data from Cassandra with = in WHERE clause, everything
> >> works fine, but when using <= or < in WHERE clause, I always get
> following
> >> Exception:
> >> >
> >> > java.sql.SQLException: No indexed columns present in by-columns clause
> >> with "equals" operator
> >> > at
> >>
> org.apache.cassandra.cql.jdbc.CassandraStatement.executeQuery(CassandraStatement.java:242)
> >> > at
> >>
> columnfamily.queries.CassandraQueries.singleColumnSelect(CassandraQueries.java:147)
> >> > ...
> >> >
> >> > My select-statement: "SELECT number FROM station WHERE number <=
> 8210;"
> >> >
> >> > Output of describe keyspace (within cli):
> >> > ColumnFamily: station
> >> > Key Validation Class: org.apache.cassandra.db.marshal.UTF8Type
> >> > Default column value validator:
> >> org.apache.cassandra.db.marshal.UTF8Type
> >> > Columns sorted by: org.apache.cassandra.db.marshal.UTF8Type
> >> > Row cache size / save period in seconds: 0.0/0
> >> > Key cache size / save period in seconds: 200000.0/14400
> >> > Memtable thresholds: 0.2109375/1440/45 (millions of
> >> ops/minutes/MB)
> >> > GC grace seconds: 864000
> >> > Compaction min/max thresholds: 4/32
> >> > Read repair chance: 1.0
> >> > Replicate on write: true
> >> > Built indexes: [station.station_number_idx]
> >> > Column Metadata:
> >> > [...]
> >> > Column Name: number
> >> > Validation Class: org.apache.cassandra.db.marshal.LongType
> >> > Index Name: station_number_idx
> >> > Index Type: KEYS
> >> > [...]
> >> >
> >> > Are the <, <=, >=, > operators not supported at this time?
> >> >
> >> > Greetings
> >> > Jens
> >> > --
> >> > NEU: FreePhone - 0ct/min Handyspartarif mit Geld-zurück-Garantie!
> >> > Jetzt informieren: http://www.gmx.net/de/go/freephone
> >> >
> >>
> >>
> >>
> >> --
> >> Jonathan Ellis
> >> Project Chair, Apache Cassandra
> >> co-founder of DataStax, the source for professional Cassandra support
> >> http://www.datastax.com
> >
> > --
> > NEU: FreePhone - 0ct/min Handyspartarif mit Geld-zurück-Garantie!
> > Jetzt informieren: http://www.gmx.net/de/go/freephone
> >
>
--
Salvador Fuentes Jr.
Re: CQL: No indexed column error when < or <= in WHERE clause
Posted by Martin von Zweigbergk <ma...@gmail.com>.
Hi Jens,
I have never used CQL myself and I have barely used Cassandra, but I
think I've seen it mentioned before on this list that you need to use
compare for equality on at least one column (as indicated by "No
indexed columns present in by-columns clause with "equals" operator").
The lookup will then be done based on that column and additional
filtering (such as for "less than") will be done on the result of the
first lookup, which can potentially be a large data set. You might
also want to redesign your data model to allow for a more efficient
lookup.
Hope that helps (despite my lack of knowledge on the subject)
Martin
On Sun, Aug 14, 2011 at 8:53 AM, Jens Hartung <ho...@gmx.de> wrote:
> I had indexed the number column in station column family. Do I also have to index another column?
>
> What I'm wondering, when I type "get station where number = 8210;" all works fine, but when I type "get station where number < 8210;" I'll get mentioned exception.
>
> Is there something, that I misunderstand?
>
> -------- Original-Nachricht --------
>> Datum: Sat, 13 Aug 2011 18:14:05 -0700
>> Von: Jonathan Ellis <jb...@gmail.com>
>> An: user@cassandra.apache.org
>> Betreff: Re: CQL: No indexed column error when < or <= in WHERE clause
>
>> This is covered in
>> http://www.datastax.com/dev/blog/whats-new-cassandra-07-secondary-indexes
>>
>> On Sat, Aug 13, 2011 at 2:49 PM, Jens Hartung <ho...@gmx.de> wrote:
>> > Hi together,
>> >
>> > first, I'm using Cassandra Version 0.8.4 and access it via CQL 1.0.3.
>> >
>> > When I select data from Cassandra with = in WHERE clause, everything
>> works fine, but when using <= or < in WHERE clause, I always get following
>> Exception:
>> >
>> > java.sql.SQLException: No indexed columns present in by-columns clause
>> with "equals" operator
>> > at
>> org.apache.cassandra.cql.jdbc.CassandraStatement.executeQuery(CassandraStatement.java:242)
>> > at
>> columnfamily.queries.CassandraQueries.singleColumnSelect(CassandraQueries.java:147)
>> > ...
>> >
>> > My select-statement: "SELECT number FROM station WHERE number <= 8210;"
>> >
>> > Output of describe keyspace (within cli):
>> > ColumnFamily: station
>> > Key Validation Class: org.apache.cassandra.db.marshal.UTF8Type
>> > Default column value validator:
>> org.apache.cassandra.db.marshal.UTF8Type
>> > Columns sorted by: org.apache.cassandra.db.marshal.UTF8Type
>> > Row cache size / save period in seconds: 0.0/0
>> > Key cache size / save period in seconds: 200000.0/14400
>> > Memtable thresholds: 0.2109375/1440/45 (millions of
>> ops/minutes/MB)
>> > GC grace seconds: 864000
>> > Compaction min/max thresholds: 4/32
>> > Read repair chance: 1.0
>> > Replicate on write: true
>> > Built indexes: [station.station_number_idx]
>> > Column Metadata:
>> > [...]
>> > Column Name: number
>> > Validation Class: org.apache.cassandra.db.marshal.LongType
>> > Index Name: station_number_idx
>> > Index Type: KEYS
>> > [...]
>> >
>> > Are the <, <=, >=, > operators not supported at this time?
>> >
>> > Greetings
>> > Jens
>> > --
>> > NEU: FreePhone - 0ct/min Handyspartarif mit Geld-zurück-Garantie!
>> > Jetzt informieren: http://www.gmx.net/de/go/freephone
>> >
>>
>>
>>
>> --
>> Jonathan Ellis
>> Project Chair, Apache Cassandra
>> co-founder of DataStax, the source for professional Cassandra support
>> http://www.datastax.com
>
> --
> NEU: FreePhone - 0ct/min Handyspartarif mit Geld-zurück-Garantie!
> Jetzt informieren: http://www.gmx.net/de/go/freephone
>
Re: CQL: No indexed column error when < or <= in WHERE clause
Posted by Jens Hartung <ho...@gmx.de>.
I had indexed the number column in station column family. Do I also have to index another column?
What I'm wondering, when I type "get station where number = 8210;" all works fine, but when I type "get station where number < 8210;" I'll get mentioned exception.
Is there something, that I misunderstand?
-------- Original-Nachricht --------
> Datum: Sat, 13 Aug 2011 18:14:05 -0700
> Von: Jonathan Ellis <jb...@gmail.com>
> An: user@cassandra.apache.org
> Betreff: Re: CQL: No indexed column error when < or <= in WHERE clause
> This is covered in
> http://www.datastax.com/dev/blog/whats-new-cassandra-07-secondary-indexes
>
> On Sat, Aug 13, 2011 at 2:49 PM, Jens Hartung <ho...@gmx.de> wrote:
> > Hi together,
> >
> > first, I'm using Cassandra Version 0.8.4 and access it via CQL 1.0.3.
> >
> > When I select data from Cassandra with = in WHERE clause, everything
> works fine, but when using <= or < in WHERE clause, I always get following
> Exception:
> >
> > java.sql.SQLException: No indexed columns present in by-columns clause
> with "equals" operator
> > at
> org.apache.cassandra.cql.jdbc.CassandraStatement.executeQuery(CassandraStatement.java:242)
> > at
> columnfamily.queries.CassandraQueries.singleColumnSelect(CassandraQueries.java:147)
> > ...
> >
> > My select-statement: "SELECT number FROM station WHERE number <= 8210;"
> >
> > Output of describe keyspace (within cli):
> > ColumnFamily: station
> > Key Validation Class: org.apache.cassandra.db.marshal.UTF8Type
> > Default column value validator:
> org.apache.cassandra.db.marshal.UTF8Type
> > Columns sorted by: org.apache.cassandra.db.marshal.UTF8Type
> > Row cache size / save period in seconds: 0.0/0
> > Key cache size / save period in seconds: 200000.0/14400
> > Memtable thresholds: 0.2109375/1440/45 (millions of
> ops/minutes/MB)
> > GC grace seconds: 864000
> > Compaction min/max thresholds: 4/32
> > Read repair chance: 1.0
> > Replicate on write: true
> > Built indexes: [station.station_number_idx]
> > Column Metadata:
> > [...]
> > Column Name: number
> > Validation Class: org.apache.cassandra.db.marshal.LongType
> > Index Name: station_number_idx
> > Index Type: KEYS
> > [...]
> >
> > Are the <, <=, >=, > operators not supported at this time?
> >
> > Greetings
> > Jens
> > --
> > NEU: FreePhone - 0ct/min Handyspartarif mit Geld-zurück-Garantie!
> > Jetzt informieren: http://www.gmx.net/de/go/freephone
> >
>
>
>
> --
> Jonathan Ellis
> Project Chair, Apache Cassandra
> co-founder of DataStax, the source for professional Cassandra support
> http://www.datastax.com
--
NEU: FreePhone - 0ct/min Handyspartarif mit Geld-zurück-Garantie!
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Re: CQL: No indexed column error when < or <= in WHERE clause
Posted by Jonathan Ellis <jb...@gmail.com>.
This is covered in
http://www.datastax.com/dev/blog/whats-new-cassandra-07-secondary-indexes
On Sat, Aug 13, 2011 at 2:49 PM, Jens Hartung <ho...@gmx.de> wrote:
> Hi together,
>
> first, I'm using Cassandra Version 0.8.4 and access it via CQL 1.0.3.
>
> When I select data from Cassandra with = in WHERE clause, everything works fine, but when using <= or < in WHERE clause, I always get following Exception:
>
> java.sql.SQLException: No indexed columns present in by-columns clause with "equals" operator
> at org.apache.cassandra.cql.jdbc.CassandraStatement.executeQuery(CassandraStatement.java:242)
> at columnfamily.queries.CassandraQueries.singleColumnSelect(CassandraQueries.java:147)
> ...
>
> My select-statement: "SELECT number FROM station WHERE number <= 8210;"
>
> Output of describe keyspace (within cli):
> ColumnFamily: station
> Key Validation Class: org.apache.cassandra.db.marshal.UTF8Type
> Default column value validator: org.apache.cassandra.db.marshal.UTF8Type
> Columns sorted by: org.apache.cassandra.db.marshal.UTF8Type
> Row cache size / save period in seconds: 0.0/0
> Key cache size / save period in seconds: 200000.0/14400
> Memtable thresholds: 0.2109375/1440/45 (millions of ops/minutes/MB)
> GC grace seconds: 864000
> Compaction min/max thresholds: 4/32
> Read repair chance: 1.0
> Replicate on write: true
> Built indexes: [station.station_number_idx]
> Column Metadata:
> [...]
> Column Name: number
> Validation Class: org.apache.cassandra.db.marshal.LongType
> Index Name: station_number_idx
> Index Type: KEYS
> [...]
>
> Are the <, <=, >=, > operators not supported at this time?
>
> Greetings
> Jens
> --
> NEU: FreePhone - 0ct/min Handyspartarif mit Geld-zurück-Garantie!
> Jetzt informieren: http://www.gmx.net/de/go/freephone
>
--
Jonathan Ellis
Project Chair, Apache Cassandra
co-founder of DataStax, the source for professional Cassandra support
http://www.datastax.com
CQL: No indexed column error when < or <= in WHERE clause
Posted by Jens Hartung <ho...@gmx.de>.
Hi together,
first, I'm using Cassandra Version 0.8.4 and access it via CQL 1.0.3.
When I select data from Cassandra with = in WHERE clause, everything works fine, but when using <= or < in WHERE clause, I always get following Exception:
java.sql.SQLException: No indexed columns present in by-columns clause with "equals" operator
at org.apache.cassandra.cql.jdbc.CassandraStatement.executeQuery(CassandraStatement.java:242)
at columnfamily.queries.CassandraQueries.singleColumnSelect(CassandraQueries.java:147)
...
My select-statement: "SELECT number FROM station WHERE number <= 8210;"
Output of describe keyspace (within cli):
ColumnFamily: station
Key Validation Class: org.apache.cassandra.db.marshal.UTF8Type
Default column value validator: org.apache.cassandra.db.marshal.UTF8Type
Columns sorted by: org.apache.cassandra.db.marshal.UTF8Type
Row cache size / save period in seconds: 0.0/0
Key cache size / save period in seconds: 200000.0/14400
Memtable thresholds: 0.2109375/1440/45 (millions of ops/minutes/MB)
GC grace seconds: 864000
Compaction min/max thresholds: 4/32
Read repair chance: 1.0
Replicate on write: true
Built indexes: [station.station_number_idx]
Column Metadata:
[...]
Column Name: number
Validation Class: org.apache.cassandra.db.marshal.LongType
Index Name: station_number_idx
Index Type: KEYS
[...]
Are the <, <=, >=, > operators not supported at this time?
Greetings
Jens
--
NEU: FreePhone - 0ct/min Handyspartarif mit Geld-zurück-Garantie!
Jetzt informieren: http://www.gmx.net/de/go/freephone
Re: CQL: How to escape single quotes?
Posted by Eric Evans <ee...@rackspace.com>.
On Wed, 2011-08-03 at 17:22 +0200, Jens Hartung wrote:
> Odd, when you generally escape special chars with an backslash.
Not in SQL (which CQL is patterned after). SQL escapes single quotes
using an additional quote character.
--
Eric Evans
eevans@rackspace.com
Re: CQL: How to escape single quotes?
Posted by Jens Hartung <ho...@gmx.de>.
Hi,
thank's for your help. This does work.
Odd, when you generally escape special chars with an backslash.
-------- Original-Nachricht --------
> Datum: Tue, 02 Aug 2011 21:42:44 -0500
> Von: Eric Evans <ee...@rackspace.com>
> An: user@cassandra.apache.org
> Betreff: Re: CQL: How to escape single quotes?
> On Wed, 2011-08-03 at 03:58 +0200, Jens Hartung wrote:
> > Is there a way, to insert Strings with single quotes to Cassandra via
> > CQL?
>
> Yes, escape them with another single quote ('aa''bb').
>
> --
> Eric Evans
> eevans@rackspace.com
>
--
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Re: CQL: How to escape single quotes?
Posted by Eric Evans <ee...@rackspace.com>.
On Wed, 2011-08-03 at 03:58 +0200, Jens Hartung wrote:
> Is there a way, to insert Strings with single quotes to Cassandra via
> CQL?
Yes, escape them with another single quote ('aa''bb').
--
Eric Evans
eevans@rackspace.com