Question

我想从t2删除如果在t1上不存在itemid，storeid，MSRTime的相同值，则t3上存在相同的itemid，storeid，MSRTime值，状态为D.在下面的示例中，我应该能够删除第二个排在t2但不是第1排。

表1：t1

itemid |storeid|MSRTime
x        y        z

表2：t2

  itemid |storeid|MSRTime
    x        y        z
    a        b        c

表3：t3

 itemid |storeid|MSRTime|status
    x        y        z   D
    a        b        c   D

我尝试使用join进行此操作，但无法达到预期效果。请帮忙。
谢谢。

Answer 1

您几乎可以按照您的描述编写查询：

declare @t1 table(itemid varchar(7),storeid varchar(9),MSRTime varchar(3))
insert into @t1(itemid,storeid,MSRTime) values
('x','y','z')
declare @t2 table(itemid varchar(7),storeid varchar(9),MSRTime varchar(3))
insert into @t2(itemid,storeid,MSRTime) values
('x','y','z'),
('a','b','c')
declare @t3 table(itemid varchar(7),storeid varchar(9),MSRTime varchar(3),status varchar(4))
insert into @t3(itemid,storeid,MSRTime,status) values
('x','y','z','D'),
('a','b','c','D')

delete from t2
from @t2 t2
    inner join
     @t3 t3
        on
            t2.itemid = t3.itemid and
            t2.storeid = t3.storeid and
            t2.MSRTime = t3.MSRTime and
            t3.status = 'D'
where
    not exists (
        select *
        from @t1 t1
        where t1.itemid = t2.itemid and
            t1.storeid = t2.storeid and
            t1.MSRTime = t2.MSRTime
    )

select * from @t2

结果：

itemid  storeid   MSRTime
------- --------- -------
x       y         z

Answer 2

应该是这样的

-- delete t2
select * 
from table2 t2 
JOIN table3 t3 on t2.itemid = t3.itemid and
                  t2.storeid = t3.storeid and
                  t2.MSRTime = t3.MSRTime
LEFT JOIN table1 t1 on t2.itemid = t1.itemid and
                       t2.storeid = t1.storeid and
                       t2.MSRTime = t1.MSRTime
where t1.itemID IS NULL

首先运行选择，如果它给你右后排，只需取消注释删除你就可以了

Answer 3

我创建了整个脚本供您参考。请使用针对您的方案的最后一个DELETE查询。那就行了。

CREATE TABLE #T1 
(itemid VARCHAR(10)
,storeid VARCHAR(10)
,MSRTime VARCHAR(10))

INSERT INTO #T1 VALUES ('x','y','z')

SELECT * FROM #T1

GO

CREATE TABLE #T2 
(itemid VARCHAR(10)
,storeid VARCHAR(10)
,MSRTime VARCHAR(10))

INSERT INTO #T2 VALUES ('x','y','z'),('a','b','c')

SELECT * FROM #T2

GO

CREATE TABLE #T3 
(itemid VARCHAR(10)
,storeid VARCHAR(10)
,MSRTime VARCHAR(10)
,status VARCHAR(10))

INSERT INTO #T3 VALUES ('x','y','z','D'),('a','b','c','D')

SELECT * FROM #T3

GO

DELETE M 
FROM #T2 AS M INNER JOIN 
(SELECT itemid,storeid,MSRTime FROM
(SELECT itemid,storeid,MSRTime FROM #T3 WHERE status='D') T1
INTERSECT 
(SELECT itemid,storeid,MSRTime FROM
            (SELECT * FROM #T2
             EXCEPT
             SELECT * FROM #T1)  T2)) X
ON X.itemid = M.itemid AND X.storeid = M.storeid AND X.MSRTime = M.MSRTime           

GO

Answer 4

不确定这是否与您的环境匹配，但是通过编程方式将您与联接进行比较的结果限制为仅具有状态值D的那些结果可能是有益的。我也会尝试使用Coalese制作复合键，这样就不必在三个单独的连接上进行匹配。

例如 -

itemid |storeid|MSRTime|Key x y z xyz a b c abc

SQL Server：根据另一个表

4 个答案: