SQL Server的支点查询只返回一行

Question

我的数据是这样的：

ID ColumnName columnnvalue 
----------------------------- 
13 seraialnew tester name 
13 serial  123123 
13 seraialnew am444 
13 serial  33333 


SELECT id,seraialnew,serial 
    FROM (
    SELECT id,columnnvalue, ColumnName FROM dbo.formValues 
) cols 
PIVOT(
    MAX(id) 
    FOR ColumnName IN(seraialnew,serial) 
)p 

，并得到单列结果不是多个

Answer 1

如果你有相同的id都只会有一个字符串，所以我换了ID，用于您的行2：

;WITH formValues AS (
SELECT * 
FROM (VALUES 
(13,'seraialnew','tester name'), 
(13,'serial','123123'), 
(14,'seraialnew','am444'), 
(14,'serial','33333') 
) as t(ID, ColumnName, columnnvalue) 
) 

SELECT id,seraialnew,serial 
    FROM (
    SELECT id,columnnvalue, ColumnName 
    FROM formValues 
) cols 
PIVOT(
    MAX(columnnvalue) 
    FOR ColumnName IN(seraialnew,serial) 
)p 

会给你：

id seraialnew serial 
13 tester name 123123 
14 am444  33333 

另一种方式：

SELECT * 
FROM (
    SELECT id, 
      columnnvalue, 
      ColumnName+CAST(ROW_NUMBER() OVER (PARTITION BY ColumnName ORDER BY ColumnName) as nvarchar(1)) as ColumnName 
    FROM formValues 
) cols 
PIVOT(
    MAX(columnnvalue) 
    FOR ColumnName IN(seraialnew1,serial1,seraialnew2,serial2) 
)p 

用相同id = 13会给你这样的：

id seraialnew1 serial1 seraialnew2 serial2 
13 am444  33333 tester name 123123