Question

有3个表相同的列但具有不同的值..结果应该只是在结果集中打印相同的组合

示例表a

col x  col y
23     a01
23     a02
24     a11
25     a12

表b

col x  col y
23     a10
23     a02
24     a11
25     a12

表c

col x  col y
23     a01
23     a02
24     a11
25     a12

希望结果为

col x  col y
24     a11
25     a12

请帮助我们获取查询

Answer 1

不熟悉ETL，但如果它只是普通的SQL，它应该是这样的：

select a.*
from a
inner join b on a.x = b.x and a.y=b.y
inner join c on a.x = c.x and a.y=c.y

Answer 2

如果要在不同的表中标识相同的行，可以使用INTERSECT运算符

WITH CTE_T1 AS
(
   SELECT [X] ,[Y]
   FROM
      (VALUES  
          (23, 'a01')
         ,(23, 'a02')
         ,(24, 'a11')
         ,(25, 'a12')
     ) T1([X],[Y])
),
CTE_T2 AS
(
   SELECT [X] ,[Y]
   FROM
      (VALUES  
          (23, 'a10')
         ,(23, 'a20')
         ,(24, 'a11')
         ,(25, 'a12')
     ) T2([X],[Y])
),
CTE_T3 AS
(
   SELECT [X] ,[Y]
   FROM
      (VALUES  
          (23, 'a40')
         ,(23, 'a50')
         ,(24, 'a11')
         ,(25, 'a12')
     ) T3([X],[Y])
)
SELECT [X],[Y] FROM CTE_T1
INTERSECT 
SELECT [X],[Y] FROM CTE_T2
INTERSECT 
SELECT [X],[Y] FROM CTE_T3

此语句产生以下结果

X           Y
----------- ----
24          a11
25          a12

(2 row(s) affected)

ETL - 需要查询

2 个答案: