Question

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
    ..            .....

我要传输数据，因此格式如下所示

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

有人建议使用数据透视表转换数据，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

但是这假设数据点是静态的，例如22,33，但是它们是动态生成的。

Answer 1

如果知道或希望的列数最大，则可以执行简单的PIVOT，否则，需要进行 DYNAMIC

示例

 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 2

我将条件聚合与row_number()一起使用：

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 3

做动态透视图很久以前。

已更新：使您的代码和名称更接近。

无论您要为PIVOT设置多少列，它都可以使用，无论1还是20都不重要

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];  
')

将表行展平为SQL Server中的列

3 个答案: