How to use SET OPTION within a DB2 stored procedure - sql

Question

I read (and tried) that I cannot use WITH UR in DB2 stored procedures. I am told that I can use SET OPTION to achieve the same. However, when I implement it in my stored procedure, it fails to compile (I moved around its location same error). My questions are:
Can I really not use WITH UR after my SELECT statements within a procedure?
Why is my stored procedure failing to compile with the below error
message?
Here is a simplified version of my code:
CREATE OR REPLACE PROCEDURE MySchema.MySampleProcedure()
DYNAMIC RESULT SETS 1
LANGUAGE SQL
SET OPTION COMMIT=*CHG
BEGIN
DECLARE GLOBAL TEMPORARY TABLE TEMP_TABLE AS (
SELECT 'testValue' as "Col Name"
) WITH DATA
BEGIN
DECLARE exitCursor CURSOR WITH RETURN FOR
SELECT *
FROM SESSION.TEMP_TABLE;
OPEN exitCursor;
END;
END
#
Error Message:
SQL0104N An unexpected token "SET OPTION COMMIT=*CHG" was found
following " LANGUAGE SQL
Here is code/error when I use WITH UR
CREATE OR REPLACE PROCEDURE MySchema.MySampleProcedure()
LANGUAGE SQL
DYNAMIC RESULT SETS 1
--#SET TERMINATOR #
BEGIN
DECLARE GLOBAL TEMPORARY TABLE TEMP_TABLE AS (
SELECT UTI AS "Trade ID" FROM XYZ WITH UR
) WITH DATA;
BEGIN
DECLARE exitCursor CURSOR WITH RETURN FOR
SELECT *
FROM SESSION.TEMP_TABLE;
OPEN exitCursor;
END;
END
#
line 9 is where the DECLARE GLOBAL TEMPORARY ... is
DB21034E The command was processed as an SQL statement because it was
not a valid Command Line Processor command. During SQL processing it
returned: SQL0109N The statement or command was not processed because
the following clause is not supported in the context where it is
used: "WITH ISOLATION USE AND KEEP". LINE NUMBER=9. SQLSTATE=42601

Answer 1

Specifying the isolation level:
For static SQL:
If an isolation-clause is specified in the statement, the value of that clause is used.
If an isolation-clause is not specified in the statement, the isolation level that was specified for the package when the package was bound to the database is used.
You need to bind the routine package with UR, since your DECLARE GTT statement is static. Before CREATE OR REPLACE use the following in the same session:
CALL SET_ROUTINE_OPTS('ISOLATION UR')
P.S.: If you want to run your routine not only 1 time in the same session without an error, use additional WITH REPLACE option of DECLARE.

Answer 2

If your Db2 server runs on Linux/Unix/Windows (Db2-LUW), then there is no such statement as SET OPTION COMMIT=*CHG , and so Db2 will throw an exception for that invalid syntax.
It is important to only use the matching Db2 Knowledge Centre for your Db2 platform and your Db2-version. Don't use Db2-Z/OS documentation for Db2-LUW development. The syntax and functionalities differ per platform and per version.
A Db2-LUW SQL PL procedure can use with ur in its internal queries, and if you are getting an error then something else is wrong. You have to use with ur in the correct syntax however, i.e in a statement that supports this clause. For your example you get the error because the clause does not appear to be valid in the depicted context. You can achieve the desired result in other ways, one of them being to populate the table in a separate statement from the declaration (e.g insert into session.temp_table("Trade ID") select uti from xyz with ur; ) and other ways are also possible.
One reason to use the online Db2 Knowledge Cenbtre documentation is that it includes sample programs, including sample SQL PL procedures, which are also available in source code form in the sample directory of your DB2-LUW server, in addition to being available on github. It is wise to study these, and get them working for you.