Question

mysql> Create Procedure sp_Getnewtask(IN sdate datetime, IN edate datetime,IN sid   int,IN tid int,OUT outmsg varchar(50))
-> begin
-> if not exists(
-> SELECT * FROM tbltask WHERE (startdate BETWEEN sdate AND edate)OR (enddate BETWEEN sdate AND edate) OR (sdate BETWEEN startdate AND enddate) OR (edate BETWEEN startdate AND enddate) OR Sid=Sid OR Tid=tid ) then
-> set outmsg = 'ADDED SUCESSFULLY';
-> else
-> set outmsg = 'RECORD ALREADY PRESENT';
-> end if;
-> end $$

mysql> select * from tbltask;

| tblid | startdate           | enddate             | Sid  | Lid  |

|     1 | 2011-05-20 00:00:00 | 2011-05-29 00:00:00 | NULL | NULL |

1 row in set (0.00 sec)

即使数据库中没有记录，它也显示为记录已存在，

如果我删除了sid，来自select查询的tid它正常工作，请提出一些想法，以便正确运行输出

当我试图打电话给程序时，它返回为，

 mysql> call sp_Getnewtask('2011-05-20','2011-05-29',6,8,@outmsg);
-> select @outmsg;
-> $$

查询OK，0行受影响（0.00秒）

| @outmsg                |

| RECORD ALREADY PRESENT |

1行（0.00秒）

但是我的实际结果应该是'添加成功'

Answer 1

“ADDED SUCCESSFULLY”只应在select语句中没有选择记录时报告，但是在call sp_Getnewtask('2011-05-20','2011-05-29',6,8,@outmsg);中给出输入变量你实际上在所有WHERE的OR条件中触发了6个条件中的4个。

编辑添加：

我运行了以下内容（包括结果）。我所做的就是更改变量的名称，这样你就不会得到一个始终为真的WHERE语句（SID=SID or TID=TID将永远为真）。我还更改了SELECT语句，以匹配您提供的表中的字段名称作为示例。

CREATE TABLE tbltask
    (
        tblid int,
        startdate datetime,
        enddate datetime,
        sid int,
        lid int
    );

INSERT INTO `tbltask`(`tblid`, `startdate`, `enddate`) VALUES (1, '2011-05-20 00:00:00','2011-05-29 00:00:00');

DELIMITER //
CREATE Procedure sp_Getnewtask(IN sdate datetime, IN edate datetime,IN inSid int,IN inLid int,OUT outmsg varchar(50))
begin
if not exists
(
    SELECT * FROM tbltask WHERE (startdate BETWEEN sdate AND edate)OR (enddate BETWEEN sdate AND edate) OR (sdate BETWEEN startdate AND enddate) OR (edate BETWEEN startdate AND enddate) OR Sid=inSid OR Lid=inLid
) then
    set outmsg = 'ADDED SUCCESSFULLY';
else
    set outmsg = 'RECORD ALREADY PRESENT';
end if;
end
//

call sp_Getnewtask('2011-05-20','2011-05-29',6,8,@outmsg);
select @outmsg;

RECORD ALREADY PRESENT

call sp_Getnewtask('2010-05-20','2010-05-29',6,8,@outmsg);
select @outmsg;

ADDED SUCCESSFULLY

目前看来，这似乎正在做它应该做的事情。如果任一日期范围应该相交，它将找到记录。如果它们不相交但是sid OR盖子匹配，那么它将找到记录。查找记录使其报告“记录已存在”

选择查询中的逻辑错误

1 个答案: