Question

SQL SERVER 2012

DECLARE @TABLE TABLE
    (
    BASENAME varchar(150),
    DESCRIPTIONS varchar(150)
    )

    insert @TABLE

    SELECT 'Accessory', 'Color' UNION ALL
    SELECT 'Accessory', 'Compatibility'UNION ALL
    SELECT 'Accessory', 'Finish'UNION ALL
    SELECT 'Accessory', 'Material'UNION ALL
    SELECT 'Accessory', 'Mount Type'UNION ALL
    SELECT 'Adapter',   'Adjustable'UNION ALL
    SELECT 'Adapter',   'Ampere'UNION ALL
    SELECT 'Adapter',   'Compatibility'UNION ALL
    SELECT 'Adapter',   'MountType'UNION ALL
    SELECT 'Adapter',   'Operation Type'UNION ALL
    SELECT 'Adapter',   'Vertical Lift'UNION ALL
    SELECT 'Adapter',   'Drawbar'UNION ALL
    SELECT 'Adapter',   'Switch'

输出

BASENAME    DESC1   DESC2   DESC3   DESC4   DESC5   DESC6   DESC7   DESC8
Accessory   Color   Compatibility   Material    Mount Type  NULL    NULL    NULL    NULL
Adapter Adjustable  Ampere  Compatibility   MountType   Operation Type  Vertical Lift   Drawbar Switch

其中一个BASENAME的DESC最大数量为DESC 50。 STUFF在这种情况下不起作用，因为它正在创建错误

错误：选择列表中的元素数量超过了允许的最大数量4096个元素。

我试过的代码：

DECLARE @Cols NVARCHAR(MAX);
DECLARE @SQL NVARCHAR(MAX);
DECLARE @Sel NVARCHAR(MAX);
DECLARE @GENERIC NVARCHAR(MAX)


SET @Cols = STUFF((SELECT distinct ',' + QUOTENAME([Description]) 
            FROM STAGING_TEMP 
            FOR XML PATH(''), TYPE
            ).value('.', 'NVARCHAR(MAX)') 
        ,1,1,'');
SET @Sel = STUFF((SELECT distinct ',' + QUOTENAME([Description]) + 
' AS DESC'+CAST(row_number () over (partition by [Generic Name] order by [description]) as varchar(250))
            FROM STAGING_TEMP 
            FOR XML PATH(''), TYPE
            ).value('.', 'NVARCHAR(MAX)') 
        ,1,1,''); 




SET @SQL = N'
SELECT DISTINCT [Generic Name], '+ @Sel+N'
FROM STAGING_TEMP
    pivot
    (
      MAX(Description) For Description IN ('+ @Cols + N')

    ) P';

EXECUTE( @SQL);

是否有其他方法可以实现所需的输出。

Answer 1

虽然您没有提供STUFF()代码段，但听起来您正在以defined in the documentation达到SQL Server SELECT / INSERT语句的限制。

Columns per SELECT statement        4,096   
Columns per INSERT statement        4,096

另请注意，每个非全局表的列数为1,024。

填充列值处理选择列表超出了允许的最大数量4096个元素

1 个答案: