Re: JDBC PostgreSQL Stored Procedure Meta-data

Apparently they are returning different data. There was a recent pull
request which might solve this.

Are you able to build the driver from github to test ?

Dave Cramer

dave.cramer(at)credativ(dot)ca
http://www.credativ.ca

On Tue, Feb 11, 2014 at 7:32 PM, Peter Damen <peter(at)peterdamen(dot)com> wrote:

> Hello,
>
> I have an issue with retrieving meta-data for Stored Procedures using the
> JDBC driver.
> I have outlined the details of my issue here:
> http://stackoverflow.com/questions/21541745/postgresql-9-jdbc-driver-returns-incorrect-metadata-for-stored-procedures#
>
> Essentially I have this example stored procedure:
>
> *CREATE FUNCTION testproc(itemid int)*
> *RETURNS TABLE(id int, name varchar(200)) AS $$*
> *BEGIN*
> * RETURN QUERY SELECT ipperson, firstname FROM testtable*
> * WHERE id = itemid;*
> *END;*
> *$$ LANGUAGE plpgsql;*
>
> And I want to get the meta-data for this query using the JDBC
> DatabaseMetaData.
>
> I have written a Java test case, it prints out the parameters returned by
> the meta-data call:
>
> *package com.hof.unittest;*
>
> *import java.sql.Connection;*
> *import java.sql.DriverManager;*
> *import java.sql.ResultSet;*
>
> *public class TestPostgres {*
>
> * public static void main(String args[]) {*
>
> * try {*
>
> * Class.forName("org.postgresql.Driver");*
>
> * Connection conn =
> DriverManager.getConnection("jdbc:postgresql://localhost:5432/testdb",
> "admin", "admin");*
>
> * ResultSet rs = conn.getMetaData().getProcedureColumns(null,
> null, "testproc", null);*
>
> * System.out.println("Driver: " +
> conn.getMetaData().getDriverVersion());*
>
> * while (rs.next()) {*
>
> * System.out.println("Parameter Name: " + rs.getString(4) +
> " Paramter Type: " + rs.getShort(5) + " Data Type: " + rs.getInt(6));*
>
> * }*
>
> * } catch (Exception e) {*
> * e.printStackTrace();*
> * }*
>
> * }*
>
> *}*
>
>
> I get different results with different JDBC drivers (against the same
> 9.1.11 server):
>
> *Driver: PostgreSQL 8.0 JDBC3 with SSL (build 313)*
> *Parameter Name: returnValue Paramter Type: 5 Data Type: 1111*
> *Parameter Name: $1 Paramter Type: 1 Data Type: 4*
>
> *Driver: PostgreSQL 9.0 JDBC4 (build 801)*
> *Parameter Name: itemid Paramter Type: 1 Data Type: 4*
> *Parameter Name: id Paramter Type: 1 Data Type: 4*
> *Parameter Name: name Paramter Type: 1 Data Type: 12*
>
> *Driver: PostgreSQL 9.3 JDBC4 (build 1100)*
> *Parameter Name: itemid Paramter Type: 1 Data Type: 4*
> *Parameter Name: id Paramter Type: 1 Data Type: 4*
> *Parameter Name: name Paramter Type: 1 Data Type: 12*
>
>
> The 8.0 driver returns meta-data in a form I can use.. it says there is
> one IN parameter and one OUT parameter (the resultset).
>
> The 9.0/3 drivers don't return an OUT parameter, and along with the single
> IN parameter, the columns returned by the resultset are also listed, and
> listed as a IN parameter.
>
> Are the 9 drivers returning the wrong meta-data?
> Was there change in how procedures were handled between JDBC3 and JDBC4?
>
> I need to get meta-data about just the IN parameters for a procedure as I
> need to dynamically prompt for input values and build the execution
> string.. ie SELECT * FROM procedure(?) OR { ? = procedure(?) }
>
> Is there any other way to get this information... querying system tables
> etc?
>
> Thanks.
>
>
>
>
>
>
>