Re: How to Raise Error ?

[Andy West]

Here's a workaround I came up with that's along the lines of the "unique constraint violation" and "non-existent procedure" techniques. However, it allows you to pass an error message that most clients will display.

Here is the stored procedure which "raises the error."



delimiter //

--
-- Raise an error.
--
CREATE PROCEDURE raise_error (
p_msg VARCHAR(128))
BEGIN
DECLARE _msg TINYINT;

-- Force an error to be raised by assigning a string to an
-- integer variable. The string will appear on the client.
SET _msg = p_msg;
END//

delimiter ;



Then, in another file, I have a trigger that calls it:
CALL raise_error ('Something bad just happened.');

When the procedure is called, I get the message "#22007Truncated incorrect INTEGER value: 'Something bad just happened.'"

These workarounds are kind of nasty, but I guess you have to make do with what you've got. By the way, I have app and SP logic that tries to prevent these errors from happening in the first place. It's really just there to prevent stupid mistakes.