MySQL存儲過程
存儲過程
定義存儲過程
delimiter ;;create procedure get_user_count()begin select count(*) as user_count from sys_user;end;; delimiter;
關於分隔符
MySQL語句分隔符爲;
,MySQL命令行程序也使用;
作爲語句分隔符。如果通過命令行執行存儲過程會解釋存儲過程自身內的;
字符,會使存儲過程中的SQL出現語法錯誤。
調用存儲過程
call get_user_count();
刪除存儲過程
drop procedure get_user_count;
使用參數
參數中有out
-- 使用參數-- in 傳遞到存儲過程-- out 從存儲過程傳出-- inout 對存儲過程傳入和傳出delimiter ;;create procedure get_count( out user_count int(10), out role_count int(10), out dict_count int(10))begin select count(*) into user_count from sys_user; select count(*) into role_count from sys_role; select count(*) into dict_count from sys_dict;end;; delimiter ;-- 調用-- 所有MySQL變量都必須以@開始-- 不能通過一個參數返回多個行和列call get_count(@user_count, @role_count, @dict_count);select @user_count, @role_count, @dict_count;
參數中有in有out
drop procedure if exists get_user_by_name; delimiter ;;create procedure get_user_by_name( in user_name varchar(45), out user_id int(10))begin select id from sys_user where user_name = user_name limit 1 into user_id;end;; delimiter ;-- 調用call get_user_by_name('admin', @admin_id);select @admin_id;
複雜一點的
-- comment 給存儲過程加註釋-- 定義delimiter ;;create procedure insert_user( in userName varchar(50), in defaultPass boolean, out userId int) comment 'create user'begin declare pass varchar(50) default null; if defaultPass then set pass = '123456'; end if; insert into sys_user(user_name, user_password, create_time) values (userName, pass, now()); select LAST_INSERT_ID() into userId;end;; delimiter ;-- 調用call insert_user('張三', false, @userId1);call insert_user('李四', true, @userId2);select @userId1, @userId2;select id, user_name, user_password, create_time from sys_user;