将行数据转换为SQL Server中的列

Question

今天,我的同事要求我将数据从垂直临时表转换为水平表.我的意思是将行转换为列.我使用了PIVOT并解决了它.但是如果数据字段重复,我遇到了移动数据的麻烦.

这是我正在处理的测试数据:

CREATE TABLE STAGING 
(
    ENTITYID INT,
    PROPERTYNAME VARCHAR(25),
    PROPERTYVALUE VARCHAR(25)
)

INSERT INTO STAGING VALUES (1, 'NAME', 'DONNA')
INSERT INTO STAGING VALUES (1, 'SPOUSE', 'HENRY')
INSERT INTO STAGING VALUES (1, 'CHILD', 'JACK')
INSERT INTO STAGING VALUES (2, 'CHILD', 'KAYALA')

我使用PIVOT将行数据显示为列:

SELECT * FROM 
(SELECT ENTITYID, PROPERTYNAME, PROPERTYVALUE FROM STAGING) AS T
PIVOT (MAX(PROPERTYVALUE) FOR PROPERTYNAME IN (NAME, SPOUSE, CHILD)) AS T2

输出是:

ENTITYID    NAME    SPOUSE  CHILD
1           DONNA   HENRY   JACK
2           NULL    NULL    KAYALA

但他希望输出类似于:

ENTITYID    NAME    SPOUSE  CHILD   CHILD
1           DONNA   HENRY   JACK    KAYALA

底线是登台表中可以有多个CHILD属性.我们需要考虑这一点,并将所有儿童移至列.

这可能吗？

Answer 1

您可以在属性名称中添加行号,以便您可以执行所需操作:

SELECT * FROM
(
SELECT ENTITYID
       , PROPERTYNAME = PROPERTYNAME + CAST(ROW_NUMBER() OVER(PARTITION BY ENTITYID, PROPERTYNAME ORDER BY PROPERTYVALUE) AS VARCHAR(5))
      ,PROPERTYVALUE
FROM #STAGING   
) AS T
PIVOT (MAX(PROPERTYVALUE) FOR PROPERTYNAME IN (NAME1, SPOUSE1, CHILD1, CHILD2, CHILD3, CHILD4, CHILD5)) AS T2

我在这里假设ENTITYID将孩子与父母联系在一起,即同一个人的所有孩子的ENTITYID为1,但你的例子显示Kayala为2.

这是一个Demo:SQL Fiddle

如果你只想要CHILD字段的数字,你可以这样:

PROPERTYNAME = CASE WHEN PROPERTYNAME LIKE '%CHILD%' THEN PROPERTYNAME + CAST(ROW_NUMBER() OVER(PARTITION BY ENTITYID, PROPERTYNAME ORDER BY PROPERTYVALUE) AS VARCHAR(5))                                                   ELSE PROPERTYNAME END

然后从IN()语句中的其他字段中删除该数字.

奖金问题 - 动态地执行以上操作: 我们不想假设人们只有一个配偶或2.3个孩子,所以我们动态地做一点:

DECLARE @cols AS NVARCHAR(MAX),
    @query  AS NVARCHAR(MAX)

SELECT @cols = STUFF((SELECT ',' + PROPERTYNAME
                    FROM (SELECT DISTINCT PROPERTYNAME = PROPERTYNAME + CAST(ROW_NUMBER() OVER(PARTITION BY ENTITYID, PROPERTYNAME ORDER BY PROPERTYVALUE) AS VARCHAR(5))
                          FROM STAGING )sub
                    ORDER BY CASE WHEN PROPERTYNAME LIKE '%NAME%' THEN 1
                        WHEN PROPERTYNAME LIKE '%SPOUSE%' THEN 2
                        WHEN PROPERTYNAME LIKE '%CHILD%' THEN 3
                    ELSE 4
                    END
                    ,RIGHT(PROPERTYNAME,1) 
                  FOR XML PATH(''), TYPE
            ).value('.', 'NVARCHAR(MAX)') 
        ,1,1,'')


SET @query = 'SELECT * FROM
                (
                SELECT ENTITYID, PROPERTYNAME = PROPERTYNAME + CAST(ROW_NUMBER() OVER(PARTITION BY ENTITYID, PROPERTYNAME ORDER BY PROPERTYVALUE) AS VARCHAR(5)),PROPERTYVALUE
                FROM STAGING   
                ) AS T
                PIVOT (MAX(PROPERTYVALUE) FOR PROPERTYNAME IN ('+@cols+')) AS T2

'
EXEC(@query)

注意:订购仅适用于配偶1-9和子女1-9,您可以调整以适应,但无论如何它是任意的.