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Posted to derby-user@db.apache.org by Pavel Bortnovskiy <pb...@jefferies.com> on 2012/06/20 18:55:18 UTC

setting column to NULL

Hello,

It seems that running the following SQL statement results in an error in Derby, while it's working fine in other DBs (such as Oracle or Sybase):

select
   a as "ColumnA",
  null as "ColumnB"
from SomeTable

java.sql.SQLSyntaxErrorException: Syntax error: Encountered "null" at line 10, column 2.
                at org.apache.derby.impl.jdbc.SQLExceptionFactory40.getSQLException(Unknown Source)
                at org.apache.derby.impl.jdbc.Util.generateCsSQLException(Unknown Source)
                at org.apache.derby.impl.jdbc.TransactionResourceImpl.wrapInSQLException(Unknown Source)
                at org.apache.derby.impl.jdbc.TransactionResourceImpl.handleException(Unknown Source)
                at org.apache.derby.impl.jdbc.EmbedConnection.handleException(Unknown Source)
                at org.apache.derby.impl.jdbc.ConnectionChild.handleException(Unknown Source)
                at org.apache.derby.impl.jdbc.EmbedPreparedStatement.<init>(Unknown Source)
                at org.apache.derby.impl.jdbc.EmbedPreparedStatement20.<init>(Unknown Source)
                at org.apache.derby.impl.jdbc.EmbedPreparedStatement30.<init>(Unknown Source)
                at org.apache.derby.impl.jdbc.EmbedPreparedStatement40.<init>(Unknown Source)
                at org.apache.derby.jdbc.Driver40.newEmbedPreparedStatement(Unknown Source)
                at org.apache.derby.impl.jdbc.EmbedConnection.prepareStatement(Unknown Source)
                at org.apache.derby.impl.jdbc.EmbedConnection.prepareStatement(Unknown Source)

Is this by design? And is there a work-around? What needs to be done to set a column to null?

Thank you,
Pavel.
Jefferies archives and monitors outgoing and incoming e-mail. The contents of this email, including any attachments, are confidential to the ordinary user of the email address to which it was addressed. If you are not the addressee of this email you may not copy, forward, disclose or otherwise use it or any part of it in any form whatsoever. This email may be produced at the request of regulators or in connection with civil litigation. Jefferies accepts no liability for any errors or omissions arising as a result of transmission. Use by other than intended recipients is prohibited. In the United Kingdom, Jefferies operates as Jefferies International Limited; registered in England: no. 1978621; registered office: Vintners Place, 68 Upper Thames Street, London EC4V 3BJ. Jefferies International Limited is authorised and regulated by the Financial Services Authority.

RE: setting column to NULL

Posted by Pavel Bortnovskiy <pb...@jefferies.com>.
Thank you so much, Rick, for your prompt response - it's very helpful.

It actually makes a lot of sense, esp. for my application.

Respectfully,
Pavel.

-----Original Message-----
From: Rick Hillegas [mailto:rick.hillegas@oracle.com]
Sent: Wednesday, June 20, 2012 1:10 PM
To: derby-user@db.apache.org
Subject: Re: setting column to NULL

On 6/20/12 9:55 AM, Pavel Bortnovskiy wrote:
>
> Hello,
>
> It seems that running the following SQL statement results in an error
> in Derby, while it's working fine in other DBs (such as Oracle or Sybase):
>
> select
>
> a as "ColumnA",
>
> null as "ColumnB"
>
> from SomeTable
>
> java.sql.SQLSyntaxErrorException: Syntax error: Encountered "null" at
> line 10, column 2.
>
> at
> org.apache.derby.impl.jdbc.SQLExceptionFactory40.getSQLException(Unkno
> wn
> Source)
>
> at org.apache.derby.impl.jdbc.Util.generateCsSQLException(Unknown
> Source)
>
> at
> org.apache.derby.impl.jdbc.TransactionResourceImpl.wrapInSQLException(
> Unknown
> Source)
>
> at
> org.apache.derby.impl.jdbc.TransactionResourceImpl.handleException(Unk
> nown
> Source)
>
> at org.apache.derby.impl.jdbc.EmbedConnection.handleException(Unknown
> Source)
>
> at org.apache.derby.impl.jdbc.ConnectionChild.handleException(Unknown
> Source)
>
> at org.apache.derby.impl.jdbc.EmbedPreparedStatement.<init>(Unknown
> Source)
>
> at org.apache.derby.impl.jdbc.EmbedPreparedStatement20.<init>(Unknown
> Source)
>
> at org.apache.derby.impl.jdbc.EmbedPreparedStatement30.<init>(Unknown
> Source)
>
> at org.apache.derby.impl.jdbc.EmbedPreparedStatement40.<init>(Unknown
> Source)
>
> at org.apache.derby.jdbc.Driver40.newEmbedPreparedStatement(Unknown
> Source)
>
> at org.apache.derby.impl.jdbc.EmbedConnection.prepareStatement(Unknown
> Source)
>
> at org.apache.derby.impl.jdbc.EmbedConnection.prepareStatement(Unknown
> Source)
>
> Is this by design? And is there a work-around? What needs to be done
> to set a column to null?
>
Hi Pavel,

Derby does not have a default datatype for untyped nulls. You need to use a cast clause in order to give the null a type. Here's an example:

connect 'jdbc:derby:memory:db;create=true';

create table t( a int );
insert into t( a ) values ( 1 );

-- untyped null fails
select null as b from t;

-- typed null succeeds
select cast( null as int ) as b from t;

Hope this helps,
-Rick
>
> Thank you,
>
> Pavel.
>
>
>             Jefferies archives and monitors outgoing and incoming
>             e-mail. The contents of this email, including any
>             attachments, are confidential to the ordinary user of the
>             email address to which it was addressed. If you are not
>             the addressee of this email you may not copy, forward,
>             disclose or otherwise use it or any part of it in any form
>             whatsoever. This email may be produced at the request of
>             regulators or in connection with civil litigation.
>             Jefferies accepts no liability for any errors or omissions
>             arising as a result of transmission. Use by other than
>             intended recipients is prohibited. In the United Kingdom,
>             Jefferies operates as Jefferies International Limited;
>             registered in England: no. 1978621; registered office:
>             Vintners Place, 68 Upper Thames Street, London EC4V 3BJ.
>             Jefferies International Limited is authorised and
>             regulated by the Financial Services Authority.
>

Jefferies archives and monitors outgoing and incoming e-mail. The contents of this email, including any attachments, are confidential to the ordinary user of the email address to which it was addressed. If you are not the addressee of this email you may not copy, forward, disclose or otherwise use it or any part of it in any form whatsoever. This email may be produced at the request of regulators or in connection with civil litigation. Jefferies accepts no liability for any errors or omissions arising as a result of transmission. Use by other than intended recipients is prohibited. In the United Kingdom, Jefferies operates as Jefferies International Limited; registered in England: no. 1978621; registered office: Vintners Place, 68 Upper Thames Street, London EC4V 3BJ. Jefferies International Limited is authorised and regulated by the Financial Services Authority.

Re: setting column to NULL

Posted by Rick Hillegas <ri...@oracle.com>.
On 6/20/12 9:55 AM, Pavel Bortnovskiy wrote:
>
> Hello,
>
> It seems that running the following SQL statement results in an error 
> in Derby, while it’s working fine in other DBs (such as Oracle or Sybase):
>
> select
>
> a as “ColumnA”,
>
> null as “ColumnB”
>
> from SomeTable
>
> java.sql.SQLSyntaxErrorException: Syntax error: Encountered "null" at 
> line 10, column 2.
>
> at 
> org.apache.derby.impl.jdbc.SQLExceptionFactory40.getSQLException(Unknown 
> Source)
>
> at org.apache.derby.impl.jdbc.Util.generateCsSQLException(Unknown Source)
>
> at 
> org.apache.derby.impl.jdbc.TransactionResourceImpl.wrapInSQLException(Unknown 
> Source)
>
> at 
> org.apache.derby.impl.jdbc.TransactionResourceImpl.handleException(Unknown 
> Source)
>
> at org.apache.derby.impl.jdbc.EmbedConnection.handleException(Unknown 
> Source)
>
> at org.apache.derby.impl.jdbc.ConnectionChild.handleException(Unknown 
> Source)
>
> at org.apache.derby.impl.jdbc.EmbedPreparedStatement.<init>(Unknown 
> Source)
>
> at org.apache.derby.impl.jdbc.EmbedPreparedStatement20.<init>(Unknown 
> Source)
>
> at org.apache.derby.impl.jdbc.EmbedPreparedStatement30.<init>(Unknown 
> Source)
>
> at org.apache.derby.impl.jdbc.EmbedPreparedStatement40.<init>(Unknown 
> Source)
>
> at org.apache.derby.jdbc.Driver40.newEmbedPreparedStatement(Unknown 
> Source)
>
> at org.apache.derby.impl.jdbc.EmbedConnection.prepareStatement(Unknown 
> Source)
>
> at org.apache.derby.impl.jdbc.EmbedConnection.prepareStatement(Unknown 
> Source)
>
> Is this by design? And is there a work-around? What needs to be done 
> to set a column to null?
>
Hi Pavel,

Derby does not have a default datatype for untyped nulls. You need to 
use a cast clause in order to give the null a type. Here's an example:

connect 'jdbc:derby:memory:db;create=true';

create table t( a int );
insert into t( a ) values ( 1 );

-- untyped null fails
select null as b from t;

-- typed null succeeds
select cast( null as int ) as b from t;

Hope this helps,
-Rick
>
> Thank you,
>
> Pavel.
>
>
>             Jefferies archives and monitors outgoing and incoming
>             e-mail. The contents of this email, including any
>             attachments, are confidential to the ordinary user of the
>             email address to which it was addressed. If you are not
>             the addressee of this email you may not copy, forward,
>             disclose or otherwise use it or any part of it in any form
>             whatsoever. This email may be produced at the request of
>             regulators or in connection with civil litigation.
>             Jefferies accepts no liability for any errors or omissions
>             arising as a result of transmission. Use by other than
>             intended recipients is prohibited. In the United Kingdom,
>             Jefferies operates as Jefferies International Limited;
>             registered in England: no. 1978621; registered office:
>             Vintners Place, 68 Upper Thames Street, London EC4V 3BJ.
>             Jefferies International Limited is authorised and
>             regulated by the Financial Services Authority.
>