在SQL Server中是否有将行转换为列的功能(在MS-Access中是可能的)？
我很困惑，因为此功能在MS-Access中可用，但在SQL Server中不可用。是设计使然，此功能未包含在SQL Server中吗？

解决方案

http://jdixon.dotnetdevelopersjournal.com/pivot_table_data_in_sql_server_2000_and_2005.htm上的示例仅在事先知道行值可以为有效的情况下才有效。例如，假设我们有一个具有自定义属性的实体，并且自定义属性被实现为子表中的行，其中子表基本上是变量/值对，而这些变量/值对是可配置的。

color red
size  big
city  Chicago

我将描述一种有效的技术。我用过了我没有在推广它，但是它有效。

要将数据旋转到我们不知道可以预先设置什么值的位置，请在没有列的情况下动态创建一个临时表。然后使用游标遍历行，为每个变量发布一个动态构建的"更改表"，以便最终临时表具有列，颜色，大小，城市。

然后，在临时表中插入一行，通过另一个游标通过变量，值对对其进行更新，然后选择它(通常与其父实体结合)，实际上使这些自定义变量/值对看起来像是内置的，在原始父实体的列中。

所描述的游标方法可能是最少使用的类似SQL的方法。如前所述，SQL 2005及以后版本的PIVOT效果很好。但是对于旧版本和非MS SQL服务器，"优化Transact-SQL"中的Rozenshtein方法(编辑：已绝版，但可从亚马逊获得：http://www.amazon.com/Optimizing-Transact-SQL- Advanced-Programming-Techniques / dp / 0964981203)非常适合透视和透视数据。
它使用点特征将基于行的数据转换为列。 Rozenshtein描述了几种情况，这是一个示例：

SELECT
    RowValueNowAColumn = 
       CONVERT(varchar,
           MAX(
          SUBSTRING(myTable.MyVarCharColumn,1,DATALENGTH(myTable.MyVarCharColumn)
       * CHARINDEX(sa.SearchAttributeName,'MyRowValue'))))
FROM
    myTable

这种方法比使用case语句更有效，并且适用于各种数据类型和SQL实现(不仅限于MS SQL)。

对于SQL Server 2005中的UNPIVOT，我发现了一篇不错的文章

列到SQL Server中的行

最好将这种事情限制在小范围内。如果我们使用的是SQL 2k，但没有可用的PIVOT功能，则我已草拟了一份存储的proc，它可以为我们完成这项工作。有点麻烦的工作，所以要尽可能地将其拆开。将以下内容粘贴到sql窗口中，并根据需要在底部编辑EXEC。如果要查看正在生成的内容，请删除中间的--s：

IF EXISTS (SELECT * FROM SYSOBJECTS WHERE XTYPE = 'P' AND NAME = 'USP_LIST_CONCAT')
DROP PROCEDURE USP_LIST_CONCAT
GO

CREATE PROCEDURE USP_LIST_CONCAT (@SourceTable NVARCHAR(1000) = '' ,@SplitColumn NVARCHAR(1000) = '' , @Deli NVARCHAR(10) = '', @KeyColumns NVARCHAR(2000) = '' , @Condition NVARCHAR(1000) = '')
AS
BEGIN
SET NOCOUNT ON

/* PROCEDURE CREATED 2010 FOR SQL SERVER 2000. SIMON HUGHES. */
/* NOTES: REMOVE --'s BELOW TO LIST GENERATED SQL. */

IF @SourceTable = '' OR @SourceTable = '?' OR @SourceTable = '/?' OR @SplitColumn = '' OR @KeyColumns = ''
BEGIN
PRINT 'Format for use:'
PRINT ' USP_LIST_CONCAT ''SourceTable'', ''SplitColumn'', ''Deli'', ''KeyColumn1,...'', ''Column1 = 12345 AND ...'''
PRINT ''
PRINT 'Description:'
PRINT 'The SourceTable should contain a number of records acting as a list of values.'
PRINT 'The SplitColumn should be the name of the column holding the values wanted.'
PRINT 'The Delimiter may be any single character or string ie ''/'''
PRINT 'The KeyColumn may contain a comma separated list of columns that will be returned before the concatenated list.'
PRINT 'The optional Conditions may be left blank or may include the following as examples:'
PRINT ' ''Column1 = 12334 AND (Column2 = ''ABC'' OR Column3 = ''DEF'')'''
PRINT ''
PRINT 'A standard list in the format:'
PRINT ' Store1, Employee1, Rabbits'
PRINT ' Store1, Employee1, Dogs'
PRINT ' Store1, Employee1, Cats'
PRINT ' Store1, Employee2, Dogs'
PRINT ''
PRINT 'Will be returned as:'
PRINT ' Store1, Employee1, Cats/Dogs/Rabbits'
PRINT ' Store1, Employee2, Dogs'
PRINT ''
PRINT 'A full ORDER BY and DISTINCT is included'
RETURN -1
END

DECLARE @SQLStatement NVARCHAR(4000)

SELECT @SQLStatement = '
DECLARE @DynamicSQLStatement NVARCHAR(4000)

SELECT @DynamicSQLStatement = ''SELECT '+@KeyColumns+', SUBSTRING(''

SELECT @DynamicSQLStatement = @DynamicSQLStatement + '' + '' + CHAR(10) +
'' MAX(CASE WHEN '+@SplitColumn+' = ''''''+RTRIM('+@SplitColumn+')+'''''' THEN '''''+@Deli+'''+RTRIM('+@SplitColumn+')+'''''' ELSE '''''''' END)''
FROM '+ @SourceTable +' ORDER BY '+@SplitColumn+'

SELECT @DynamicSQLStatement = @DynamicSQLStatement + '' ,2,7999) List'' + CHAR(10) + ''FROM '+ @SourceTable+''' + CHAR(10) +'''+CASE WHEN @Condition = '' THEN '/* WHERE */' ELSE 'WHERE '+@Condition END+ '''+ CHAR(10) + ''GROUP BY '+@KeyColumns+'''

SELECT @DynamicSQLStatement = REPLACE(@DynamicSQLStatement,''( +'',''('')

-- SELECT @DynamicSQLStatement -- DEBUG ONLY
EXEC (@DynamicSQLStatement)'

EXEC (@SQLStatement)

END
GO

EXEC USP_LIST_CONCAT 'MyTableName', 'ColumnForListing', 'Delimiter', 'KeyCol1, KeyCol2', 'Column1 = 123456'

我有以下格式的数据

Survey_question_ID

电子邮件(用户)

回答

1次调查有13个问答
我想要的期望输出是

用户--- Survey_question_ID1 --- Survey_question_ID2

电子邮件---答案---答案........等等

这是SQL Server 2000的解决方案，因为字段数据类型为TEXT。

DROP TABLE #tmp

DECLARE @tmpTable  TABLE
(
emailno NUMERIC,
question1 VARCHAR(80),
question2 VARCHAR(80),
question3 VARCHAR(80),
question4 VARCHAR(80),
question5 VARCHAR(80),
question6 VARCHAR(80),
question7 VARCHAR(80),
question8 VARCHAR(80),
question9 VARCHAR(80),
question10 VARCHAR(80),
question11 VARCHAR(80),
question12 VARCHAR(80),
question13 VARCHAR(8000)
)

DECLARE @tmpTable2  TABLE
(
emailNumber NUMERIC
)

DECLARE @counter INT
DECLARE @Email INT

SELECT @counter =COUNT(DISTINCT ans.email) FROM answers ans WHERE ans.surveyname=100430 AND ans.qnpkey BETWEEN 233702 AND 233714
SELECT * INTO #tmp FROM @tmpTable
INSERT INTO @tmpTable2 (emailNumber) SELECT DISTINCT CAST(ans.email AS NUMERIC) FROM answers ans WHERE ans.surveyname=100430 AND ans.qnpkey BETWEEN 233702 AND 233714

WHILE @counter >0

BEGIN

        SELECT TOP 1 @Email= emailNumber FROM @tmpTable2
        INSERT INTO @tmpTable (emailno) VALUES (@Email )

        Update @tmpTable set question1=CAST(answer as VARCHAR(80)) from answers ans where ans.surveyname=100430 and ans.qnpkey = 233702 and ans.email=@Email
        Update @tmpTable set question2=CAST(answer as VARCHAR(80)) from answers ans where ans.surveyname=100430 and ans.qnpkey = 233703 and email=@email
        Update @tmpTable set question3=CAST(answer as VARCHAR(80)) from answers ans where ans.surveyname=100430 and ans.qnpkey = 233704 and email=@email
        Update @tmpTable set question4=CAST(answer as VARCHAR(80)) from answers ans where ans.surveyname=100430 and ans.qnpkey = 233705 and email=@email
        Update @tmpTable set question5=CAST(answer as VARCHAR(80)) from answers ans where ans.surveyname=100430 and ans.qnpkey = 233706 and email=@email
        Update @tmpTable set question6=CAST(answer as VARCHAR(80)) from answers ans where ans.surveyname=100430 and ans.qnpkey = 233707 and email=@email
        Update @tmpTable set question7=CAST(answer as VARCHAR(80)) from answers ans where ans.surveyname=100430 and ans.qnpkey = 233708 and email=@email
        Update @tmpTable set question8=CAST(answer as VARCHAR(80)) from answers ans where ans.surveyname=100430 and ans.qnpkey = 233709 and email=@email
        Update @tmpTable set question9=CAST(answer as VARCHAR(80)) from answers ans where ans.surveyname=100430 and ans.qnpkey = 233710 and email=@email
        Update @tmpTable set question10=CAST(answer as VARCHAR(80)) from answers ans where ans.surveyname=100430 and ans.qnpkey = 233711 and email=@email
        Update @tmpTable set question11=CAST(answer as VARCHAR(80)) from answers ans where ans.surveyname=100430 and ans.qnpkey = 233712 and email=@email
        Update @tmpTable set question12=CAST(answer as VARCHAR(80)) from answers ans where ans.surveyname=100430 and ans.qnpkey = 233713 and email=@email
        Update @tmpTable set question13=CAST(answer as VARCHAR(8000)) from answers ans where ans.surveyname=100430 and ans.qnpkey = 233714 and email=@email

        insert into #tmp select * from  @tmpTable       

        DELETE FROM @tmpTable       
        DELETE FROM @tmpTable2 WHERE emailNumber= @Email

        set @counter =@counter -1

End

select * from #tmp