DB2 - How do I create a Stored Procedure that ignores errors? - stored-procedures

Question

I am trying to create a simple stored procedure in DB2 that performs the following actions:
Drop table "DELETE_ME"
Create table "DELETE_ME"
Insert into table "DELETE_ME"
Basically, if the table DELETE_ME already exists, the stored procedure executes fine. If it does not exist, then the Stored Procedure fails with the following error:
Lookup Error - DB2 Database Error: ERROR [42704] [IBM][DB2/LINUXX8664] SQL0204N "SARTS02T.DELETE_ME" is an undefined name.
I completely understand this. However, I was hoping to set the procedure up to ignore this error (and all errors) that way the procedure can work as a deployment script as well. On the first deployment, it will ignore the drop table line and jump right to building the table.
I found a CREATE PROCEDURE option called CONTINUE AFTER FAILURE however I am receiving an error. Please see my code and error below. Thanks for your help!!!
CODE:
CREATE OR REPLACE PROCEDURE TEST_PROC LANGUAGE SQL CONTINUE AFTER FAILURE
BEGIN
DROP TABLE DELETE_ME;
CREATE TABLE DELETE_ME (
COLUMN_A DECIMAL(5)
);
INSERT INTO DELETE_ME (COLUMN_A) VALUES (69);
COMMIT;
END;
ERROR:
Lookup Error - DB2 Database Error: ERROR [42601] [IBM][DB2/LINUXX8664] SQL0104N An unexpected token "CONTINUE AFTER FAILURE" was found following "ST_PROC LANGUAGE SQL". Expected tokens may include: "<space>".

Answer 1

The BEGIN ... END section is called a compound statement which allows various declarations and other statements, including other compound statements, to be included inside it.
You'll want to declare a condition handler. You could do it something like this.
CREATE OR REPLACE PROCEDURE TEST_PROC
LANGUAGE SQL
COMMIT ON RETURN YES
BEGIN
DECLARE CONTINUE HANDLER FOR SQLSTATE '42704' -- or SQLEXCEPTION
BEGIN
-- insert any code here when DROP fails
END;
DROP TABLE DELETE_ME;
CREATE TABLE DELETE_ME
( COLUMN_A DECIMAL(5)
);
INSERT INTO DELETE_ME (COLUMN_A)
VALUES (69);
END;