Question

我有一个数据表，如下所示

User Year  Points  Value
A    1997  1       10
A    1997  2       30
A    1997  3       40
A    1999  1       70
B    1993  1       7
B    1993  3       4
C    2001  1       10
.....

我希望将表格转换为：

User   Year  Points1  Points2  Points3 ....
A      1997  10       30       40
A      1999  70       null     null
B      1993  7        null     4
C      2001  10       null     null
......

点的范围在编译时是未知的，因此它不仅仅是从1到3。它几乎就像将Points作为新表中的列标题。我认为SQL PIVOT是一个不错的选择，但我没有运气好玩。我正在使用SQL 2008。

Answer 1

由于您提到SQL PIVOT我猜您正在使用SQL Server 2005或更高版本或Oracle 11g

SQL 2005

SELECT [user], year, [1] as Point1, [2] as Point2, [3] as Point3 
FROM
(

SELECT  [user], year , points, Value
    FROM table ) AS SourceTable
PIVOT
(
SUM(Value)
FOR Points IN ([1], [2], [3])
) AS PivotTable
ORDER BY [user]

请参阅此data.se query

的工作示例

Oracle 11g

如果您使用的是Oracle 11g，那将是类似的事情（不确定字段别名）

SELECT *
FROM   (
        SELECT  user, year , points, Value
        FROM table )
PIVOT  (SUM(Value) AS sum_value FOR (Points ) IN ('1' as Point1 , 
                                                  '2' as Point2, 
                                                 '3' as Point3))
Order by User;

Answer 2

也许这会有所帮助：

首先创建一些测试数据：

CREATE TABLE tblPoints ([User] VARCHAR(100), [Year] INT,Points INT,Value INT)
INSERT INTO tblPoints
SELECT 'A',1997,1,10 UNION ALL
SELECT 'A',1997,2,30 UNION ALL
SELECT 'A',1997,3,40 UNION ALL
SELECT 'A',1999,1,70 UNION ALL
SELECT 'B',1993,1,7 UNION ALL
SELECT 'B',1993,3,4 UNION ALL
SELECT 'C',2001,1,10

汇总列：

DECLARE @cols VARCHAR(MAX)
SELECT  @cols = COALESCE(@cols + ','+QUOTENAME('Points'+Points),
                     QUOTENAME('Points'+Points))
FROM
    (
        SELECT
            ROW_NUMBER() OVER(PARTITION BY tblPoints.Points ORDER BY tblPoints.Points) AS RowNbr,
            CAST(tblPoints.Points AS VARCHAR(5)) AS Points
        FROM 
            tblPoints
    ) AS tbl
WHERE
    tbl.RowNbr=1

然后创建动态sql并执行它：

DECLARE @query NVARCHAR(4000)=
N'SELECT
    *
FROM
(
    SELECT
        tblPoints.[User],
        tblPoints.[Year],
        ''Points''+CAST(tblPoints.Points AS VARCHAR(5)) AS Points,
        tblPoints.Value
    FROM
        tblPoints
) AS p
PIVOT
(
    SUM(Value) FOR Points IN('+@cols+')
) AS pvt
ORDER BY [User]'

EXECUTE(@query)

因为我不想要点表：

DROP TABLE tblPoints

sql表pivot或transform

2 个答案: