MySQL Stored Procedure Error Handling
DELIMITER $$

CREATE PROCEDURE `myProcedure`(OUT o_error_status varchar(50))
MY_BLOCK: BEGIN

 DECLARE EXIT handler for 1062 set o_error_status := "Duplicate entry in table";
 DECLARE EXIT handler for 1048 set o_error_status := "Trying to populate a non-null column with null value";
-- declare handlers ad nauseum here....

 DECLARE EXIT handler for sqlexception set o_error_status:= "Generic SQLException. You'll just have to figure out the SQLSTATE yourself...." ;

-- Procedure logic that might error to follow here...

END MY_BLOCK$$

SHOW ERRORS LIMIT 1   -- for SQL-state > 2
SHOW WARNINGS LIMIT 1 -- for SQL-state 1,2

DECLARE EXIT HANDLER FOR SQLSTATE SQLEXCEPTION .....;

SELECT RAISE_ERROR_unable_to_update_basket;

ERROR 1054 (42S22): Unknown column 'RAISE_ERROR_unable_to_update_basket' in 'field list'