Question

我需要能够为每个具有最大价值的名称选择第一行。

我有一张包含以下内容的表格：

id  name  value

0   JOHN  123
1   STEVE 125
2   JOHN  127
3   JOHN  126

所以我希望回来：

id  name  value

1   STEVE 125
2   JOHN  127

关于如何执行此操作的MSSQL语法有任何想法吗？

Answer 1

指定SQL Server时，未指定版本。如果您使用的是SQL Server 2005或更高版本，则可以执行以下操作：

With RankedItems As
    (
        Select id, name, value
            , Row_Number() Over ( Partition By name Order By value Desc, id Asc ) As ItemRank
        From Table
    )
Select id, name, value
From RankedItems
Where ItemRank = 1

Answer 2

尝试：

SELECT
    MIN(id) as id,dt.name,dt.value
    FROM (SELECT
              name,MAX(value) as value
              FROM YourTable
              GROUP BY name
         ) dt
        INNER JOIN YourTable t ON dt.name=t.name and dt.value=t.value
    GROUP BY dt.name,dt.value

尝试一下：

DECLARE @YourTable table (id int, name varchar(10), value int)
INSERT @YourTable VALUES (0, 'JOHN',  123)
INSERT @YourTable VALUES (1, 'STEVE', 125)
INSERT @YourTable VALUES (2, 'JOHN',  127)
INSERT @YourTable VALUES (3, 'JOHN',  126)

--extra data not in the question, shows why you need the outer group by
INSERT @YourTable VALUES (4, 'JOHN',  127)
INSERT @YourTable VALUES (5, 'JOHN',  127)
INSERT @YourTable VALUES (6, 'JOHN',  127)
INSERT @YourTable VALUES (7, 'JOHN',  127)

SELECT
    MIN(id) as id,dt.name,dt.value
    FROM (SELECT
              name,MAX(value) as value
              FROM @YourTable
              GROUP BY name
         ) dt
        INNER JOIN @YourTable t ON dt.name=t.name and dt.value=t.value
    GROUP BY dt.name,dt.value
    ORDER BY id

输出：

id          name       value
----------- ---------- -----------
1           STEVE      125
2           JOHN       127

(2 row(s) affected)

Answer 3

您可以执行类似

的操作

SELECT id, name, value
FROM (SELECT id, name, value
             ROWNUMBER() OVER (PARTITION BY name ORDER BY value DESC) AS r
      FROM table) AS x
WHERE x.r = 1 ;

这在SQL Server 2000及更早版本中不起作用，但在SQL Server 2005和2008中速度将非常快

Answer 4

怎么样：

SELECT a.id, a.name, b.maxvalue
  FROM mytbl a
 INNER JOIN (SELECT id, max(value) as maxvalue
               FROM mytbl
           GROUP BY id) b ON b.id = a.id

Answer 5

SELECT a.id, a.name, a.value
  FROM mytbl a
 INNER JOIN (SELECT name, max(value) as maxvalue
               FROM mytbl
           GROUP BY name) b ON b.name = a.name and b.maxvalue = a.value

SQL Server独特的问题

5 个答案: