DROP PROCEDURE is used to delete a stored procedure.
DROP FUNCTION is used to delete a stored function.
When a stored function is deleted, an existing stored function may become invalid. A stored function that satisfies the following condition becomes invalid:
In this case, use ALTER ROUTINE to re-create the invalidated stored function.
When a stored function is deleted, an existing stored procedure may become invalid. An existing stored procedure that satisfies the following condition becomes invalid:
In this case, use the ALTER PROCEDURE statement or ALTER ROUTINE to re-create the invalidated stored procedure.
When a stored function is deleted, an existing trigger may become invalid. An existing trigger that satisfies the following condition becomes invalid:
In this case, use the ALTER TRIGGER statement or ALTER ROUTINE to re-create the invalidated trigger.