Transactions within MySql Stored Procedures - mysql

Question

I am trying to use a transaction within a MySQL Stored Procedure.
Specifically, update a user table with amended data from a temporary record. from another table.
then once transferred, delete the temporary record.
I have created the code below, which when executed returns the string "transaction has succeeded".
However, nothing is actually updated and the temporary record is Not deleted.
Both SQL statements, when executed separately work Just fine, the first one does the update, the second does the delete.
Can anyone enlighten me as to what may be wrong?
BEGIN
-- set a default response
DECLARE response varchar(48) DEFAULT "the transaction has failed.";
DECLARE EXIT HANDLER FOR SQLEXCEPTION
BEGIN
ROLLBACK;
-- set vars
SET response = "the transaction has failed, you may have already updated the account.";
select response;
END;
START TRANSACTION;
-- we are inserting data, using information from another table
update user, updateUserNamesAndNumbers
SET user.firstName = updateUserNamesAndNumbers.firstName,
user.lastName = updateUserNamesAndNumbers.lastName,
user.landline = updateUserNamesAndNumbers.landline,
user.mobile = updateUserNamesAndNumbers.mobile
WHERE
updateUserNamesAndNumbers.uuid = transferCode
AND
updateUserNamesAndNumbers.userId= user.user_id
;
-- finally delete the original tuple
DELETE from updateUserNamesAndNumbers
where uuid= transferCode ;
SET response="The transaction has succeeded";
COMMIT;
SELECT response;
END

Answer 1

Change the implicit join to an explicit join
update user join updateUserNamesAndNumbers on updateUserNamesAndNumbers.uuid = transferCode

Answer 2

I've Partially answered my own Question.
Thanks to P.Salmon, for Querying the transferCode variable.
It turns out I had defined the string as varchar(24), but the input was actually bigger than that.
So once I sorted that, the code worked, but only the first time.
I still need to have a really good think about this, as a second call to the same routine with the same transferCode input, where the temporary tuple had already been deleted by the first call, does not throw the MySQL Exception, as I thought it should. So "its Still Thinking Cap On Time"