Question

我有这样的查询

select  top 1* from table1 where organizationID= 79 order by D_Index desc
select  top 1* from table1 where organizationID= 87 order by D_Index desc
select  top 1* from table1 where organizationID= 19 order by D_Index desc

这里我试图获取表1中针对organizationID的最后数据..表示79,87和19的最后数据，并尝试与union结合，但这显示错误

select  top 1* from table1 where organizationID= 79 order by D_Index desc union all 
select  top 1* from table1 where organizationID= 87 order by D_Index desc union all 
select  top 1* from table1 where organizationID= 19 order by D_Index desc

如果我写这个

  select  top 1* from table1 where organizationID= 79  union all 
    select  top 1* from table1 where organizationID= 87  union all 
    select  top 1* from table1 where organizationID= 19  
order by D_Index desc

然后显示第一行79和87以及最后一行19但我想要最后一行对79,87和19

任何帮助？

Answer 1

;WITH CTE as
(
  SELECT
    *,
    row_number() over (partition by organizationID order by D_Index desc) rn
  FROM
    table1
  WHERE organizationID in (19,79,87)
)
SELECT *
FROM CTE
WHERE rn = 1

没有CTE（根据要求）

SELECT *
FROM 
  (
    SELECT
      *,
      row_number() over (partition by organizationID order by D_Index desc) rn
    FROM
      table1
    WHERE organizationID in (19,79,87)
  ) x
WHERE rn = 1

Answer 2

@ t-clausen.dk的回答是这里的方法，但是这里有一种方法可以使你当前的方法有效：

SELECT * FROM
    (SELECT TOP 1 * FROM table1 WHERE organizationID = 79 ORDER BY D_Index DESC) t1
UNION ALL
SELECT * FROM
    (SELECT TOP 1 * FROM table1 WHERE organizationID = 87 ORDER BY D_Index DESC) t2
UNION ALL
SELECT * FROM
    (SELECT TOP 1 * FROM table1 WHERE organizationID = 19 ORDER BY D_Index DESC) t3;

发生错误是因为ORDER BY无法出现在联合查询（或任何查询）的中间。但是如果我们将您的查询包装为子查询，那么我们可以对它们使用ORDER BY。

同样，使用ROW_NUMBER是这里的方法，但是如果您需要使用这样的语法，则可以正确编写。

SQL中的最后一行

2 个答案: