Question

我试图根据一个值是否存在来排除特定值。所以我的数据类似于下面的数据。

Client    StoreType   
-------   ---------
   1         1     
   1         2      
   1         2     
   2         2      
   3         1   
   3         2
   4         2
   4         2

因此，在此示例中，StoreType = 1存在时，我希望在该Client的StoreType = 2时排除。但是，如果该Client不存在StoreType = 1，我希望在StoreType = 2时包含。所以我想得到的结果是：

Client    StoreType
-------   ---------
   1         1
   2         2
   3         1
   4         2
   4         2

有谁知道你怎么能这样做？

Answer 1

SELECT Client, StoreType
FROM YourTable AS t1
WHERE StoreType = 1
OR (NOT EXISTS (SELECT 1 FROM YourTable AS t2
                WHERE t1.Client = t2.Client
                AND t2.StoreType = 1)
    AND StoreType = 2)

DEMO

Answer 2

IF EXISTS(SELECT Client, StoreType
FROM tableFoo
WHERE StoreType = 1)

SELECT Client, StoreType
FROM tableFoo
WHERE StoreType = 1

ELSE 
IF NOT EXISTS (SELECT Client, StoreType
FROM tableFoo
WHERE StoreType = 1)

SELECT Client, StoreType
FROM tableFoo
WHERE StoreType = 2

如果SQL中存在一个值，则排除除1之外的所有值

2 个答案: