Question

我有以下内容正确地带回了3套结果

SELECT        TOP (1) rid,score, weight
FROM            dbo.tblThree
WHERE        (caseNo = '111111111')
ORDER BY rID DESC

SELECT        TOP (1) rid,score, weight
FROM            dbo.tblTwo
WHERE        (caseNo = '111111111')
ORDER BY rID DESC

SELECT        TOP (1) rid,score, weight
FROM            dbo.tblOne
WHERE        (caseNo = '111111111')
ORDER BY rID DESC

由于UNION ALL语句，在它们之间添加ORDER BY失败。但是，如果我摆脱它们，它会失败，因为它没有得到最新的记录。

这有更简单的解决方案吗？我想要的是一个输出3行的SQL语句。

Answer 1

尝试以下方法：

select * from ( select top (1) rid, score, weight
                from dbo.tblThree
                where caseNo = '111111111'
                order by rid desc) t1
union all
select * from ( select top (1) rid, score, weight
                from dbo.tblTwo
                where caseNo = '111111111'
                order by rid desc) t2
union all
select * from ( select top (1) rid, score, weight
                from dbo.tblOne
                where caseNo = '111111111' 
                order by rid desc) t3

Answer 2

您可以使用以下内容获得所需的输出：

WITH data AS (
    SELECT        rid,score, weight, ROW_NUMBER() OVER (ORDER BY rID DESC) AS rn
    FROM            dbo.tblThree
    WHERE        (caseNo = '111111111')
    UNION ALL 
    SELECT        rid,score, weight, ROW_NUMBER() OVER (ORDER BY rID DESC) AS rn
    FROM            dbo.tblTwo
    WHERE        (caseNo = '111111111')
    UNION ALL
    SELECT        rid,score, weight, ROW_NUMBER() OVER (ORDER BY rID DESC) AS rn
    FROM            dbo.tblOne
    WHERE        (caseNo = '111111111')
)
SELECT *
FROM    data 
WHERE   rn = 1

Answer 3

尝试此查询

select rID,score, weight from 
(SELECT        TOP (1) rID,score, weight,ROW_NUMBER() over(order by rID) as a
FROM            dbo.tblThree
WHERE        (caseNo = '111111111')
UNION ALL
SELECT        TOP (1) rid,score, weight,ROW_NUMBER() over(order by rID) as a
FROM            dbo.tblTwo
WHERE        (caseNo = '111111111')
UNION ALL
SELECT        TOP (1) rid,score, weight,ROW_NUMBER() over(order by rID) as a
FROM            dbo.tblOne
WHERE        (caseNo = '111111111'))t

Answer 4

;WITH CTE1 as
(
  SELECT        TOP (1) rid,score, weight
  FROM            dbo.tblThree
  WHERE        (caseNo = '111111111')
  ORDER BY rID DESC
), CTE2 as
(
  SELECT        TOP (1) rid,score, weight
  FROM            dbo.tblTwo
  WHERE        (caseNo = '111111111')
  ORDER BY rID DESC
), CTE3 as
(
  SELECT        TOP (1) rid,score, weight
  FROM            dbo.tblOne
  WHERE        (caseNo = '111111111')
  ORDER BY rID DESC
)
SELECT
  rid,score, weight 
FROM CTE1
UNION ALL
SELECT
  rid,score, weight 
FROM CTE2
UNION ALL
SELECT
  rid,score, weight 
FROM CTE3

在UNION ALL上选择最大记录

4 个答案: