Alex Stetsenko

It is a bit confusing that MySQL function supports return statement but stored procedure does not.

However there is LEAVE statement which can serve the same goal:

this statement is used to exit the flow control construct that has the given label. It can be used within BEGIN … END or loop constructs (LOOP, REPEAT, WHILE).

For example the stored procedure below returns the passed number only if it is non-zero:

DROP PROCEDURE IF EXISTS TestProc;
CREATE PROCEDURE TestProc
(
  vTestNum INT
)
TOP:BEGIN
 
IF vTestNum = 0 THEN
  LEAVE TOP;
END IF;
 
SELECT vTestNum;
 
END;