MySQL 9.4 Release Notes
        
LEAVE label
        This statement is used to exit the flow control construct that
        has the given label. If the label is for the outermost stored
        program block, LEAVE exits the
        program.
      
        LEAVE can be used within
        BEGIN ...
        END or loop constructs
        (LOOP,
        REPEAT,
        WHILE).
      
For an example, see Section 15.6.5.5, “LOOP Statement”.