sql-server - 无法在 SQL Server 2008 R2 中进行动态透视

Question

我需要在 SQL Server 2008 R2 中进行旋转。我有一个包含员工记录的 EMP 表，然后是一个存储相关子记录的子表。

现在我想在输出中为每个员工创建一条记录。我不确定如何将 Child1Name、Child2Name、Child3Name .... Child99Name 放在列侧。下面是示例输入和输出。TIA。

Answer 1

    /*
    My Sql server 2012
    the code below can run at above 2005
    */
    set nocount on
    ;with EmpTable as (
                        select * 
                        from (values(1,'John'),(2,'Tim'),(3,'Steve')) as a(ID,Name)
                      ),
           ChildTable as(
                         select * 
                         from (values(1,1,'Tina'),(2,1,'Mike'),(3,2,'Mona'),(4,3,'Zane'),(5,3,'Diana'),(6,3,'Marry')) as b(ID,EmpID,Name)
                        ),
           sourceData as(
                         select a.Name,b.EmpID,b.Name as ChildName,row_number() over(partition by EmpID order by B.ID,b.Name) as rn
                         from EmpTable as a inner join ChildTable as b on a.ID = b.EmpID

                        )
          select EmpID,Name,[1] as Child1Name,[2] as Child2Name,[3] as Child3Name
          from sourceData as  a pivot (max(ChildName) for rn in([1],[2],[3]))as b
    /*
    EmpID       Name  Child1Name Child2Name Child3Name
    ----------- ----- ---------- ---------- ----------
    1           John  Tina       Mike       NULL
    2           Tim   Mona       NULL       NULL
    3           Steve Zane       Diana      Marry
    */   



/*
Dynamic  pivoting
My Sql server 2012
the code below can run at above 2005
*/
--step 1 :
set nocount on
;with EmpTable as (
                    select * 
                    from (values(1,'John'),(2,'Tim'),(3,'Steve')) as a(ID,Name)
                  ),
       ChildTable as(
                     select * 
                     from (values(1,1,'Tina'),(2,1,'Mike'),(3,2,'Mona'),(4,3,'Zane'),(5,3,'Diana'),(6,3,'Marry')) as b(ID,EmpID,Name)
                    ),
       sourceData as(
                     select a.Name,b.EmpID,b.Name as ChildName,row_number() over(partition by EmpID order by B.ID,b.Name) as rn
                     from EmpTable as a inner join ChildTable as b on a.ID = b.EmpID

                    )
      select * into #a
      from sourceData 

--Step 2: 
      declare @PivotColumn as varchar(5000),@DisplayColumn as varchar(5000),@Sql as nvarchar(4000)
     ;with columnData as ( select distinct rn from #a)
      select  @PivotColumn = isnull(@PivotColumn,'')+quotename(cast(rn as varchar))+',',@DisplayColumn= isnull(@DisplayColumn,'')+quotename(cast(rn as varchar))+' as Child'+cast(rn as varchar)+'Name,'
      from columnData
      set @PivotColumn = left(@PivotColumn,len(@PivotColumn)-1)
      set @DisplayColumn = left(@DisplayColumn,len(@DisplayColumn)-1)
     set @Sql = 'select EmpID,Name,'+@DisplayColumn+' from #a as a pivot(max(ChildName) for rn in ('+@PivotColumn+')) as b'

     exec sp_executesql @sql
/*
EmpID       Name  Child1Name Child2Name Child3Name
----------- ----- ---------- ---------- ----------
1           John  Tina       Mike       NULL
2           Tim   Mona       NULL       NULL
3           Steve Zane       Diana      Marry
*/