Re: jdbc cursor positioning

From: "G(dot)Nagarajan" <gnagarajan(at)dkf(dot)de>
To: "Dave Cramer" <Dave(at)micro-automation(dot)net>
Cc: <pgsql-jdbc(at)postgresql(dot)org>
Subject: Re: jdbc cursor positioning
Date: 2002-10-07 17:15:27
Message-ID: NFBBIOPECKPCJJHHBOGJEEMLDIAA.gnagarajan@dkf.de
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I was trying to figure out a way to retrieve
a particular set of rows from the cursor. If I have
10,000 rows and need to take only the records between
5600 and 5700, "MOVE" would have been ideal. Using "FETCH"
would mean that the 5600 records have to be transferred
from the server. so I guess the only option left is to
use the offset and limit options in the query.

Thanks,
Nagarajan.

> -----Original Message-----
> From: pgsql-jdbc-owner(at)postgresql(dot)org
> [mailto:pgsql-jdbc-owner(at)postgresql(dot)org]On Behalf Of Dave Cramer
> Sent: Monday, October 07, 2002 6:50 PM
> To: G.Nagarajan
> Cc: pgsql-jdbc(at)postgresql(dot)org
> Subject: Re: [JDBC] jdbc cursor positioning
>
>
> Sorry,
>
> I should have taken the move lines out, there is no way to tell if they
> succeed.
>
> Dave
> On Mon, 2002-10-07 at 12:51, G.Nagarajan wrote:
> > hi Dave,
> >
> > I get the following error when I execute the program
> >
> > Caught Exception: Kann Anzahl der veränderten Zeilen nicht
> ermitteln: MOVE
> > Kann Anzahl der veränderten Zeilen nicht ermitteln: MOVE
> > at
> >
> org.postgresql.core.QueryExecutor.receiveCommandStatus(QueryExecut
> or.java:18
> > 2)
> > at
> org.postgresql.core.QueryExecutor.execute(QueryExecutor.java:80)
> > at org.postgresql.Connection.ExecSQL(Connection.java:398)
> > at org.postgresql.jdbc2.Statement.execute(Statement.java:130)
> > at
> org.postgresql.jdbc2.Statement.executeUpdate(Statement.java:73)
> > at fz.core.database.CursorTest.main(CursorTest.java:23)
> >
> > It tells that it cannot determine the number of modified rows.
> >
> > I am using Postgresql 7.1.3 and 7.2 jdbc driver. I will check
> with the beta
> > driver and see
> > if the error goes away.
> >
> > Regards,
> > Nagarajan.
> >
> > > -----Original Message-----
> > > From: pgsql-jdbc-owner(at)postgresql(dot)org
> > > [mailto:pgsql-jdbc-owner(at)postgresql(dot)org]On Behalf Of Dave Cramer
> > > Sent: Monday, October 07, 2002 3:43 PM
> > > To: David Wall
> > > Cc: pgsql-jdbc(at)postgresql(dot)org
> > > Subject: Re: [JDBC] jdbc cursor positioning
> > >
> > >
> > > This is a sample program which uses cursors
> > >
> > > con = getConnection();
> > > con.setAutoCommit( false );
> > > Statement stmt = con.createStatement();
> > >
> > > int result = stmt.executeUpdate( "declare test cursor
> for select *
> > > from orders" );
> > > System.out.println( "Created cursor, result is " + result );
> > > result = stmt.executeUpdate( "move 0 in dave");
> > > result = stmt.executeUpdate( "move -"+result+"in dave");
> > >
> > > for(;;)
> > > {
> > > rs = stmt.executeQuery("fetch forward 5 in test");
> > > if ( !rs.next() )
> > > break;
> > > }
> > >
> > > while(rs.next()){
> > > System.out.println("Id -->" + rs.getObject(1).toString());
> > > }
> > > rs.close();
> > > con.commit();
> > > con.close();
> > >
> > >
> > > Dave
> > > On Sun, 2002-10-06 at 22:57, David Wall wrote:
> > > > > No, postgres fully supports cursors, the problem must be
> > > somewhere else.
> > > >
> > > > How do you make use of them from JDBC?
> > > >
> > > > David
> > > >
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