mysql 存储过程 基础例子

DELIMITER //  -- 定义分隔符，防止作为sql语句执行
drop procedure if exists pr_add;
create procedure pr_add( )
begin
   declare c int;
   set c = 2;
   if c = 1 then
    insert into ONLINE_USER_INFO values(1,'admin','厉害了','');
   else delete from ONLINE_USER_INFO where user_code = 1;
   end if;
   while c < 10 do 
    insert into ONLINE_USER_INFO values(c+2,'admin','厉害了','');
    set c = c + 1;
   end while;
   test_loop:loop
   delete from ONLINE_USER_INFO where user_code = c-2;
   set c = c - 1;
   if c < 8 then 
    leave test_loop;
   end if;
   end loop;
end //   -- 必须，否则创建存储过程失败
DELIMITER ;
call pr_add();

2.事务回滚

DELIMITER //  -- 定义分隔符，防止作为sql语句执行
drop procedure if exists pr_add;
create procedure pr_add( )
begin
   declare c int;
   declare t_error INTEGER default 0;
DECLARE CONTINUE HANDLER FOR SQLEXCEPTION SET t_error=1; --出现sql异常则设置t_error为1
   set c = 1;
START TRANSACTION;   --开启事务
   if c = 1 then
    insert into ONLINE_USER_INFO values(1,'admin','厉害了','');
   else delete from ONLINE_USER_INFO where user_code = 1;
   end if;
   while c < 10 do 
    insert into ONLINE_USER_INFO values(c+2,'admin','厉害了','');
    set c = c + 1;
   end while;
   test_loop:loop
   delete from ONLINE_USER_INFO where user_code = c-2;
   set c = c - 1;
   if c < 8 then 
    insert into ONLINE_USER_INFO values('admin','厉害了','');    --出现异常
    leave test_loop;
   end if;
   end loop;
   if t_error = 1 then 
    ROLLBACK;    --执行回滚操作
   else 
commit;   --提交sql操作
   end if;
end //   -- 存储的结束
DELIMITER ;
call pr_add()