Example of how you can change the library list in a SQL stored procedure before calling an external RPG program that may require that Library.

SQLProcedureChangeLibraryListCallExternalRPG.sql

CREATE PROCEDURE MYLIB.SQLSTOREDPROCEDURE (
	IN MYNUMBER DECIMAL(9, 0),
	INOUT RESULT CHAR(1) )
	LANGUAGE SQL 
	BEGIN 
   DECLARE CMD CHAR ( 300 ) DEFAULT ' ' ; 
   DECLARE CURRENTDATE CHAR ( 8 ) DEFAULT ' ' ; 
			
	--Ignore the error message that occurs if you add the library list twice
	--Create a variable that has the SQLSTATE value and create a CONTINUE HANDLER for that 
	--SQLSTATE
   DECLARE LibraryAlreadyAdded CONDITION FOR SQLSTATE '38501';
   DECLARE CONTINUE HANDLER FOR LibraryAlreadyAdded BEGIN END; 
 
   SET CMD = 'ADDLIBLE MYLIB2' ; 
   SET CURRENTDATE = YEAR(NOW()) || RIGHT('0' || MONTH(NOW()),2) || RIGHT('0' || DAY(NOW()),2)     ;

	--CALL Command to add MYLIB2 to the Library list
   CALL QSYS . QCMDEXC ( CMD , 0000000300.00000 ) ;
	--CALL EXTERNAL RPG PROGRAM WITH INOUT PARAM OUTPUTDATE
   CALL MYLIB.MYRPGPGM (MYNUMBER,OUTPUTDATE);

   IF (CURRENTDATE>OUTPUTDATE) THEN
       SET RESULT = 'N';
   ELSE
       SET RESULT = 'Y';
   END IF;
END  ;

--Call the SQL Stored Procedure with a value
CALL MYLIB.SQLSTOREDPROCEDURE(987654321,' ');