I am running into a behavior with a postgresql function with a SETOF refcursor's returning multiple columns. Not sure if there is a different way to retrieve a SETOF refcursor's with variable columns? Alternatively can I return a primitive value and a refcursor from the same function. I tried specifying this as OUT parameters without any luck. In Oracle you can pass this in functions:
Platform:postgresql-x64-9.0 (PostgreSQL 9.0.1, compiled by Visual C++ build 1500, 64-bit)Java1.6JDBC4 Postgresql Driver, Version 9.0-801

Function:CREATE OR REPLACE FUNCTION test() RETURNS SETOF refcursor AS$BODY$DECLAREref1 refcursor;ref2 refcursor;BEGIN OPEN ref1 FOR SELECT 1; RETURN NEXT ref1; OPEN ref2 FOR SELECT 2, 3; RETURN NEXT ref2; RETURN;END; $BODY$ LANGUAGE plpgsql

Java Code:CallableStatement cs = conn.prepareCall("{ call test() }");ResultSet rs = cs.executeQuery();
while (rs.next()) { System.out.println(rs.getString(1)); ResultSet rs2 = (ResultSet)rs.getObject(1); while (rs2.next()) { ResultSetMetaData rsmd = rs2.getMetaData(); int numberOfColumns = rsmd.getColumnCount(); System.out.println("numberOfColumns: " + numberOfColumns); System.out.println(rs2.getString(1)); System.out.println(rs2.getString(2)); }}
Output:<unnamed portal 1>numberOfColumns: 11org.postgresql.util.PSQLException: The column index is out of range: 2, number of columns: 1. at org.postgresql.jdbc2.AbstractJdbc2ResultSet.checkColumnIndex(AbstractJdbc2ResultSet.java:2680) at org.postgresql.jdbc2.AbstractJdbc2ResultSet.checkResultSet(AbstractJdbc2ResultSet.java:2697) at org.postgresql.jdbc2.AbstractJdbc2ResultSet.getString(AbstractJdbc2ResultSet.java:1872) at PgBlob.test(PgBlob.java:64) at PgBlob.main(PgBlob.java:37)
It appears the second result-set takes in the number of columns from the first irrespective of the number of columns from the second. If the change the function to return 2 refcursor's with same number of columns then it works as expected.
Function:CREATE OR REPLACE FUNCTION test() RETURNS SETOF refcursor AS$BODY$DECLAREref1 refcursor;ref2 refcursor;BEGIN OPEN ref1 FOR SELECT 1, null; RETURN NEXT ref1; OPEN ref2 FOR SELECT 2, 3; RETURN NEXT ref2; RETURN;END; $BODY$ LANGUAGE plpgsql
Output:<unnamed portal 1>numberOfColumns: 214<unnamed portal 2>numberOfColumns: 223