Re: CallableStatement and getUpdateCount

Sam Lawrence wrote:
> I have a query about using CallableStatement with functions that return
> a SETOF. I know the "Calling Stored Functions" documentation says use a
> Statement or a PreparedStatement - I'm in the process of porting over a
> database and would like to leave my calling code the same - that means
> CallableStatement (more in a moment).
>
> First, an example. A simple function (I know the SETOF is redundant in
> this example, normally it wouldn't be) -
>
> CREATE OR REPLACE FUNCTION cstest()
> RETURNS SETOF integer AS
> $$
> SELECT 1;
> $$
> LANGUAGE 'sql' VOLATILE;
>
> The calling code -
>
> Class.forName("org.postgresql.Driver");
> Connection con = DriverManager.getConnection("...");
>
> CallableStatement cs = con.prepareCall("{call cstest()}");
> cs.execute();
>
> System.out.println("update count - should be -1? " + cs.getUpdateCount());
>
> ResultSet rs = cs.getResultSet();
> while(rs.next())
> {
> System.out.println(rs.getInt(1));
> }
> rs.close();
> cs.close();
> con.close();
>
> The code works fine and returns the record correctly. My problem is the
> getUpdateCount after the execute - from the java.sql.Statement
> documentation "if the result is a ResultSet object or there are no more
> results, -1 is returned". It actually comes back as 1. Is this a bug or
> have I missed something?
>
> I'm running PostgreSQL 8.3.0 with postgresql-8.3-603.jdbc4.

Hmmm. getUpdateCount() is defined in
org/postgresql/jdbc2/AbstractJdbc2Statement.java as

public int getUpdateCount() throws SQLException
{
[...]
if (isFunction)
return 1;
[...]
}

So it will always return 1 for a callable statement.

There is no comment in the source. Does anybody know why that is?

Yours,
Laurenz Albe