如何通过组合两个CTE来获得期望的结果？

Question

我有两个CTE的，首先

;WITH CTE AS (SELECT A.* 
        , Row_NUMBER() Over (Partition by ID order by Date asc) RN 
      FROM TABLE A) 
    SELECT Sum(Weight) as IN_WT 
    FROM CTE 
    WHERE RN = 1 and name='dev1' 

然后

;WITH CTE AS (SELECT B.* 
        , Row_NUMBER() Over (Partition by ID order by Date desc) RN1 
      FROM TABLE B) 
    SELECT Sum(Weight) AS out_wt 
    FROM CTE 
    WHERE RN1 = 1 and name='dev1' 

现在我有一个reuiremnt输出应结合起来，并得到in_wt，out_wt.I试图结合两者的CTE的，但没”没有达到预期的结果。我们该怎么做？

Answer 1

这是简单的解决办法，我发现，

“快速&脏”的做法将是两个包裹你的查询在其他两种CTE的SELECT (SELECT IN_WT FROM CTE1), (SELECT OUT_WT FROM CTE2)

Answer 2

如果这两个热膨胀系数访问相同表，暗示在问题的疑问，那么你可以使用下面的查询，以获得期望的结果：

;WITH CTE AS (
    SELECT *, 
      Row_NUMBER() Over (Partition by ID order by Date asc) RN1, 
      Row_NUMBER() Over (Partition by ID order by Date desc) RN2 
    FROM TABLE 
) 
SELECT SUM(CASE WHEN RN1 = 1 THEN Weight ELSE 0 END) as IN_WT, 
     SUM(CASE WHEN RN2 = 1 THEN Weight ELSE 0 END) as OUT_WT 
FROM CTE 
WHERE 1 IN (RN1, RN2) AND name = 'dev1' 

Answer 3

您有2个表和有它们之间没有任何关系。 然后结合2查询简单地像

;WITH cteA AS (SELECT A.* 
       , Row_NUMBER() Over (Partition by ID order by Date asc) RN 
      FROM TABLEA A), 
     cteB AS (SELECT B.* 
       , Row_NUMBER() Over (Partition by ID order by Date desc) RN 
      FROM TABLEB B) 
SELECT 
     ( SELECT Sum(Weight) 
     FROM cteA 
     WHERE RN = 1 and name='dev1' 
    ) as IN_WT, 
     ( SELECT Sum(Weight) 
     FROM cteB 
     WHERE RN = 1 and name='dev1' 
    ) as OUT_WT