Question

我有一个表MySeekCatTable，其结构为：

       SeekId  CatId

        J       1<= i<=45

在此表中，每个SeekId都有三个CatId。表MySeekCatTable引用带有外键的两个表：

以SeekTable为主键的第一个表SeekId如下：

        SeekId  Name

          1     John

          2     Kelly

以CatTable为主键的第二个表CatId如下：

        CatId   Name

          1     Cat1

          2     Cat2

我需要的是，我必须编写一个查询，其格式为其SeekId中的每个CatId三个：

      SeekId      A          B           C

        1         Cat1       Cat2        Cat3

        i         Cati       Catj        Catk

Answer 1

;WITH cte
     AS (SELECT SeekId,
                CatId,
                ct.Name,
                ROW_NUMBER() OVER (PARTITION BY SeekId ORDER BY CatId) AS RN
         FROM   MySeekCatTable sk
                JOIN CatTable ct
                  ON sk.CatId = ct.CatId)
SELECT SeekId,
       MAX(CASE WHEN RN = 1 THEN Name END) AS A,
       MAX(CASE WHEN RN = 2 THEN Name END) AS B,
       MAX(CASE WHEN RN = 3 THEN Name END) AS C
FROM   cte
GROUP  BY SeekId

Transact SQL Query-Pivot-SQL

1 个答案: