1、书写存储过程
DROP PROCEDURE IF EXISTS count_has_same_name_proc;
CREATE PROCEDURE count_has_same_name_proc (xname VARCHAR(50 ) )
BEGIN
SELECT COUNT(* ) FROM t_user WHERE name = xname;
END;
2、函数书写执行
错误写法
DROP FUNCTION IF EXISTS count_has_same_name_func;
CREATE FUNCTION count_has_same_name_func ( xname VARCHAR(50 ) )
RETURNS INT
BEGIN
SELECT COUNT(id ) FROM t_user WHERE name = xname;
END;
正确写法
DROP FUNCTION IF EXISTS count_has_same_name_func;
CREATE FUNCTION count_has_same_name_func ( xname VARCHAR(50 ) )
RETURNS INT
BEGIN
DECLARE s INT ;
SELECT COUNT(id ) into s FROM t_user WHERE name = xname;
RETURN s;
END;
注：trigger和function都需要写成 select ...into 这种句式，否者会报1415错误。