Re: CallableStatements - Mailing list pgsql-jdbc

As Dave has said, since stored procedures in Postgres can only return a
single value, there is little to be gained from CallableStatements that
you can't already do with regular Statements or PreparedStatements.

The way to call stored procedures in postgres is via a select statement.
  Thus to call procedure foo(), you would issue the query 'select
foo()'.  Since this is a standard select statement, you can use either a
regular Statement or PreparedStatement to get the result of this stored
procedure.

Having said that, if you wanted to contribute a CallableStatement
implementation for postgres we would be glad to accept it.  Remember
that this is an open source project, features get added by people who
want or need them.  If you need CallableStatements implement them an
submit a patch.

thanks,
--Barry



Dave Cramer wrote:

> Well, given that postgres doesn't support the notion of returning a
> result set from a stored procedure; I'm not sure what benefit this would
> be.
>
> Regards,
>
> Dave
>
> -----Original Message-----
> From: pgsql-jdbc-owner@postgresql.org
> [mailto:pgsql-jdbc-owner@postgresql.org] On Behalf Of
> email@gregorybittar.com
> Sent: Friday, November 23, 2001 6:47 PM
> To: pgsql-jdbc@postgresql.org
> Subject: [JDBC] CallableStatements
>
>
> CallableStatements weren't in Postgres as of the last time I checked,
> version 7.1.
>
> The JDBC specification has lots of goodies in it, such as examining a
> server's metadata and sending cursors backwards and forwards over result
> sets.  However, from the perspective of a Java programmer,
> CallableStatements are essential tools for communicating with a database
> server.
>
> Without the benefit of CallableStatements, all efforts at efficiency are
> wasted.  The hallmark of any robust system is distributed processing,
> which requires invoking stored procedures on foreign machines.  Doing so
> through CallableStatements would
> (a) accomplish work and (b) retrieve a result code in one logical
> network transmission.  Without CallableStatements, retrieving the result
> code not only requires more programming infrastructure, but also taxes
> the application at runtime as the Java application tries to discover
> what the result of the stored procedure was. This method requires an
> additional deletion to purge the logged result code record, lest the log
> grow, slowing searches. Therefore, we are looking at considerably more
> processing done, 2 or 3 transmissions, where 1 should suffice.
>
> Consequently, I would hope that CallableStatements are recognized as a
> very important part of the JDBC puzzle.
>
>
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