将表行压平为SQL Server中的列[重复]

Question

这个问题在这里已有答案：

• Insert and update in a cursor in SQL Server 1回答

我有下面的SQL表，其中包含随机生成的数据

  Code          Data
    SL Payroll    22
    SL Payroll    33
    SL Payroll    43
    ..            .....

我想传输数据，因此格式如下所示

Code         Data1   Data2   Data3  ..
SL Payroll   22       33      43    ....  

有人建议使用Pivot表来转换数据，如下所示

SELECT Code,
       [22] Data1,
       [33] Data2,
       [43] Data3
FROM
    (
      SELECT *
      FROM T
    ) TBL
    PIVOT
    (
      MAX(Data) FOR Data IN([22],[33],[43])
    ) PVT

但这假设数据点是静态的，如22,33，但它们是动态生成的。

Answer 1

我会使用条件聚合和row_number()：

select code,
       max(case when seqnum = 1 then code end) as code_1,
       max(case when seqnum = 2 then code end) as code_2,
       max(case when seqnum = 3 then code end) as code_3
from (select t.*,
             row_number() over (partition by code order by data) as seqnum
      from t
     ) t
group by code;

Answer 2

如果你知道或最大数量的所需列，你可以做一个简单的PIVOT，否则，你需要去DYNAMIC

例

 Select *
  From (
        Select [Code]
              ,[Data]
              ,[Col] = concat('Data',Row_Number() over (Partition By [Code] Order by 1/0))
         From  YourTable
       ) src
 Pivot (max([Data]) for [Col] in ([Data1],[Data2],[Data3],[Data4],[Data5])) pvt

返回

Code        Data1   Data2   Data3   Data4   Data5
SL Payroll  22      33      43      NULL    NULL

Answer 3

做动态支点我做了很长一段路。

更新：更接近您的代码和表名。

这适用于PIVOT所需的许多列，无论是1还是20都无关紧要

DECLARE @SelectFieldNameList as varchar(8000)
DECLARE @SelectFieldNameListCount as varchar(8000)
Set @SelectFieldNameList = ''
Set @SelectFieldNameListCount = ''

-- this section selects the list of firm location names and puts them in a string to be used in the pivot
-- it does it for the field select list and the count select using ISNULL so it puts a 0 if no counts returned
SELECT top (999999) @SelectFieldNameList = @SelectFieldNameList + case when @SelectFieldNameList = '' then '' else ', ' end 
+ '[' + Data + ']', 
@SelectFieldNameListCount = @SelectFieldNameListCount + case when @SelectFieldNameListCount = '' then '' else ', ' end 
+ 'ISNULL([' + Data + '], ''0'')' + Data 
From TableName
Where Data IS NOT NULL AND Ltrim(Data) <> ''
Group by Data

-- just for testing
select @SelectFieldNameList, @SelectFieldNameListCount


-- NOW USE THE ABOVE TO get the data pivoted with your dyanic fields
EXEC('
SELECT [Code], ' + @SelectFieldNameListCount + '
FROM (  
    SELECT [Code], Data, Sum(CountTotal) as CountTotal
    From TableName
    Group by [Code], Data
) AS TableToBePivoted
PIVOT (  
    SUM(CountTotal) 
    FOR Data IN (' + @SelectFieldNameList + ')  
) AS PivotedTable
order by [Code];  
')