Skip site navigation (1) Skip section navigation (2)

Re: Error while retrieving generated keys

From: "Mike Clements" <mclement(at)progress(dot)com>
To: "Gary Greenberg" <gary(at)icontrol(dot)com>, <pgsql-jdbc(at)postgresql(dot)org>
Subject: Re: Error while retrieving generated keys
Date: 2007-03-09 21:40:11
Message-ID: (view raw, whole thread or download thread mbox)
Lists: pgsql-jdbcpgsql-odbc
I recently found a workaround that seems to perform the same as keygen -
all in one RDB round trip, obviating the need for a second round trip to
fetch the key from the sequence.
If you add a "RETURNING pk" clause to the INSERT statement, the JDBC
execute() for this insert statement will return a ResultSet instead of a
row count. You treat this ResultSet exactly like the one that would have
been returned from GetGeneratedKeys(). That is, call next() and then
call get() to get the pk.
In other words, you never call GetGeneratedKeys(). Instead, after
calling statement.execute() you call statement.getResultSet().
Looking at the source code for the latest JDBC driver, it looks like it
would not be too difficult to implement the
Connection.prepareStatement() call that specifies the columns to return
as generated keys. Perhaps you could in this call add a RETURNING clause
to the SQL for the same columns... just a thought, I haven't gone down
that path myself because the above approach worked just fine for me.

From: pgsql-jdbc-owner(at)postgresql(dot)org
[mailto:pgsql-jdbc-owner(at)postgresql(dot)org] On Behalf Of Gary Greenberg
Sent: Friday, March 09, 2007 10:37 AM
To: pgsql-jdbc(at)postgresql(dot)org
Subject: Re: [JDBC] Error while retrieving generated keys

I see it now. It should have been, however, mentioned in documentation
for the JDBC driver.

I have also reviewed a recent thread on a
similar topic. 

The gist of it was how to overcome the deficiency of JDBC3 driver using
JDBC1 features.

It looks to me that you, guys, are missing the primary point:


Ability to retrieve auto-generated key is one of the key features of
JDB3. It exists for over 2 years and all JDBC3 drivers I know of,
supports it.

A lot of frameworks (JPA, Hibernate, etc.) are relying on it. It means
that they won't work with PostgreSQL.

It also means that developers must do a lot of extra tinkering to adopt
many standard apps for PostgreSQL.

In essence it means that PostgreSQL has fallen into the third world of
database engines.

I used to work a lot with PostgreSQL in mid-90s and loved it but I just
recently returned to this world from working with Oracle, Sybase, etc.

I am really disappointed that PostgreSQL is becoming a fossil.


If there are no plans to make this feature work in the very near future,
I'll be pushing for replacement of the engine.



From: QuanZongliang [mailto:quanzongliang(at)hotmail(dot)com] 
Sent: Thursday, March 08, 2007 8:48 PM
To: Gary Greenberg
Cc: pgsql-jdbc(at)postgresql(dot)org
Subject: RE: [JDBC] Error while retrieving generated keys


348    public PreparedStatement prepareStatement(String sql, int
349    throws SQLException
350    {
351        if (autoGeneratedKeys != Statement.NO_GENERATED_KEYS)
352            throw new PSQLException("Returning autogenerated
keys is not supported."), PSQLState.NOT_IMPLEMENTED);
353        return prepareStatement(sql);
354    }

So, it is not supported.

Only the prepareStatement(sql, Statement.NO_GENERATED_KEYS) can be used.


From: gary(at)icontrol(dot)com
To: pgsql-jdbc(at)postgresql(dot)org
Subject: [JDBC] Error while retrieving generated keys
Date: Thu, 8 Mar 2007 19:49:52 -0800

My application trew the following exception:


org.postgresql.util.PSQLException: Returning autogenerated keys is not





I am using 8.2-504.jdbc3 driver with the PostgreSql 8.0.8 on SUSE Linux.

I have not seen anywhere in the documentation that this standard JDBC3
feature is not supported.

Can anyone explain it to me, please.

In response to

pgsql-odbc by date

Next:From: Dave CramerDate: 2007-03-09 23:32:33
Subject: Re: Error while retrieving generated keys
Previous:From: Heikki LinnakangasDate: 2007-03-09 21:30:30
Subject: Re: Error while retrieving generated keys

pgsql-jdbc by date

Next:From: Mike ClementsDate: 2007-03-09 21:44:57
Subject: Re: Fetching generated keys
Previous:From: Heikki LinnakangasDate: 2007-03-09 21:30:30
Subject: Re: Error while retrieving generated keys

Privacy Policy | About PostgreSQL
Copyright © 1996-2017 The PostgreSQL Global Development Group