使用SQL Server中的"Pivot"将行转换为列

Question

我已经阅读了MS数据透视表上的内容,但我仍然遇到问题.

我有一个正在创建的临时表,我们会说第1列是商店号,第2列是周数,最后第3列是某种类型的总和.周数也是动态的,商店数是静态的.

Store      Week     xCount
-------    ----     ------
102        1        96
101        1        138
105        1        37
109        1        59
101        2        282
102        2        212
105        2        78
109        2        97
105        3        60
102        3        123
101        3        220
109        3        87

我希望它作为一个数据透视表出来,像这样:

Store        1          2          3        4        5        6....
----- 
101        138        282        220
102         96        212        123
105         37        
109

将数字存储在侧面,将数字存储在顶部.

Answer 1

如果您使用的是SQL Server 2005+,则可以使用该PIVOT函数将数据从行转换为列.

听起来你需要使用动态sql如果周未知,但最初使用硬编码版本更容易看到正确的代码.

首先,这里有一些快速表定义和使用数据:

CREATE TABLE #yt 
(
  [Store] int, 
  [Week] int, 
  [xCount] int
);

INSERT INTO #yt
(
  [Store], 
  [Week], [xCount]
)
VALUES
    (102, 1, 96),
    (101, 1, 138),
    (105, 1, 37),
    (109, 1, 59),
    (101, 2, 282),
    (102, 2, 212),
    (105, 2, 78),
    (109, 2, 97),
    (105, 3, 60),
    (102, 3, 123),
    (101, 3, 220),
    (109, 3, 87);

如果您的值已知,那么您将对查询进行硬编码:

select *
from 
(
  select store, week, xCount
  from yt
) src
pivot
(
  sum(xcount)
  for week in ([1], [2], [3])
) piv;

请参阅SQL Demo

然后,如果您需要动态生成周数,您的代码将是:

DECLARE @cols AS NVARCHAR(MAX),
    @query  AS NVARCHAR(MAX)

select @cols = STUFF((SELECT ',' + QUOTENAME(Week) 
                    from yt
                    group by Week
                    order by Week
            FOR XML PATH(''), TYPE
            ).value('.', 'NVARCHAR(MAX)') 
        ,1,1,'')

set @query = 'SELECT store,' + @cols + ' from 
             (
                select store, week, xCount
                from yt
            ) x
            pivot 
            (
                sum(xCount)
                for week in (' + @cols + ')
            ) p '

execute(@query);

请参阅SQL Demo.

动态版本,生成week应转换为列的数字列表.两者都给出相同的结果:

| STORE |   1 |   2 |   3 |
---------------------------
|   101 | 138 | 282 | 220 |
|   102 |  96 | 212 | 123 |
|   105 |  37 |  78 |  60 |
|   109 |  59 |  97 |  87 |

Answer 2

这是动态的周数.

这里有完整的示例:SQL Dynamic Pivot

DECLARE @DynamicPivotQuery AS NVARCHAR(MAX)
DECLARE @ColumnName AS NVARCHAR(MAX)

--Get distinct values of the PIVOT Column 
SELECT @ColumnName= ISNULL(@ColumnName + ',','') + QUOTENAME(Week)
FROM (SELECT DISTINCT Week FROM #StoreSales) AS Weeks

--Prepare the PIVOT query using the dynamic 
SET @DynamicPivotQuery = 
  N'SELECT Store, ' + @ColumnName + ' 
    FROM #StoreSales
    PIVOT(SUM(xCount) 
          FOR Week IN (' + @ColumnName + ')) AS PVTTable'
--Execute the Dynamic Pivot Query
EXEC sp_executesql @DynamicPivotQuery

Answer 3

我之前通过使用子查询实现了同样的目标.因此,如果您的原始表名为StoreCountsByWeek,并且您有一个单独的表列出了商店ID,那么它将如下所示:

SELECT StoreID, 
    Week1=(SELECT ISNULL(SUM(xCount),0) FROM StoreCountsByWeek WHERE StoreCountsByWeek.StoreID=Store.StoreID AND Week=1),
    Week2=(SELECT ISNULL(SUM(xCount),0) FROM StoreCountsByWeek WHERE StoreCountsByWeek.StoreID=Store.StoreID AND Week=2),
    Week3=(SELECT ISNULL(SUM(xCount),0) FROM StoreCountsByWeek WHERE StoreCountsByWeek.StoreID=Store.StoreID AND Week=3)
FROM Store
ORDER BY StoreID

这种方法的一个优点是语法更清晰,并且更容易连接到其他表以将其他字段拉入结果中.

我的轶事结果是,在不到一秒的时间内完成了几千行的查询,我实际上有7个子查询.但正如评论中所指出的那样,以这种方式执行它的计算成本更高,因此如果您希望它运行在大量数据上,请小心使用此方法.

Answer 4

这是你可以做的:

SELECT * 
FROM yourTable
PIVOT (MAX(xCount) 
       FOR Week in ([1],[2],[3],[4],[5],[6],[7])) AS pvt

DEMO

Answer 5

我正在编写一个可能对此有用的sp，基本上，此sp枢转任何表并返回枢转的新表或仅返回数据集，这是执行它的方法：

Exec dbo.rs_pivot_table @schema=dbo,@table=table_name,@column=column_to_pivot,@agg='sum([column_to_agg]),avg([another_column_to_agg]),',
        @sel_cols='column_to_select1,column_to_select2,column_to_select1',@new_table=returned_table_pivoted;

请注意，在参数@agg中，列名必须与'['，参数必须以逗号结尾','

SP

Create Procedure [dbo].[rs_pivot_table]
    @schema sysname=dbo,
    @table sysname,
    @column sysname,
    @agg nvarchar(max),
    @sel_cols varchar(max),
    @new_table sysname,
    @add_to_col_name sysname=null
As
--Exec dbo.rs_pivot_table dbo,##TEMPORAL1,tip_liq,'sum([val_liq]),sum([can_liq]),','cod_emp,cod_con,tip_liq',##TEMPORAL1PVT,'hola';
Begin

    Declare @query varchar(max)='';
    Declare @aggDet varchar(100);
    Declare @opp_agg varchar(5);
    Declare @col_agg varchar(100);
    Declare @pivot_col sysname;
    Declare @query_col_pvt varchar(max)='';
    Declare @full_query_pivot varchar(max)='';
    Declare @ind_tmpTbl int; --Indicador de tabla temporal 1=tabla temporal global 0=Tabla fisica

    Create Table #pvt_column(
        pivot_col varchar(100)
    );

    Declare @column_agg table(
        opp_agg varchar(5),
        col_agg varchar(100)
    );

    IF  EXISTS (SELECT * FROM sys.objects WHERE object_id = OBJECT_ID(@table) AND type in (N'U'))
        Set @ind_tmpTbl=0;
    ELSE IF OBJECT_ID('tempdb..'+ltrim(rtrim(@table))) IS NOT NULL
        Set @ind_tmpTbl=1;

    IF  EXISTS (SELECT * FROM sys.objects WHERE object_id = OBJECT_ID(@new_table) AND type in (N'U')) OR 
        OBJECT_ID('tempdb..'+ltrim(rtrim(@new_table))) IS NOT NULL
    Begin
        Set @query='DROP TABLE '+@new_table+'';
        Exec (@query);
    End;

    Select @query='Select distinct '+@column+' From '+(case when @ind_tmpTbl=1 then 'tempdb.' else '' end)+@schema+'.'+@table+' where '+@column+' is not null;';
    Print @query;

    Insert into #pvt_column(pivot_col)
    Exec (@query)

    While charindex(',',@agg,1)>0
    Begin
        Select @aggDet=Substring(@agg,1,charindex(',',@agg,1)-1);

        Insert Into @column_agg(opp_agg,col_agg)
        Values(substring(@aggDet,1,charindex('(',@aggDet,1)-1),ltrim(rtrim(replace(substring(@aggDet,charindex('[',@aggDet,1),charindex(']',@aggDet,1)-4),')',''))));

        Set @agg=Substring(@agg,charindex(',',@agg,1)+1,len(@agg))

    End

    Declare cur_agg cursor read_only forward_only local static for
    Select 
        opp_agg,col_agg
    from @column_agg;

    Open cur_agg;

    Fetch Next From cur_agg
    Into @opp_agg,@col_agg;

    While @@fetch_status=0
    Begin

        Declare cur_col cursor read_only forward_only local static for
        Select 
            pivot_col 
        From #pvt_column;

        Open cur_col;

        Fetch Next From cur_col
        Into @pivot_col;

        While @@fetch_status=0
        Begin

            Select @query_col_pvt='isnull('+@opp_agg+'(case when '+@column+'='+quotename(@pivot_col,char(39))+' then '+@col_agg+
            ' else null end),0) as ['+lower(Replace(Replace(@opp_agg+'_'+convert(varchar(100),@pivot_col)+'_'+replace(replace(@col_agg,'[',''),']',''),' ',''),'&',''))+
                (case when @add_to_col_name is null then space(0) else '_'+isnull(ltrim(rtrim(@add_to_col_name)),'') end)+']'
            print @query_col_pvt
            Select @full_query_pivot=@full_query_pivot+@query_col_pvt+', '

            --print @full_query_pivot

            Fetch Next From cur_col
            Into @pivot_col;        

        End     

        Close cur_col;
        Deallocate cur_col;

        Fetch Next From cur_agg
        Into @opp_agg,@col_agg; 
    End

    Close cur_agg;
    Deallocate cur_agg;

    Select @full_query_pivot=substring(@full_query_pivot,1,len(@full_query_pivot)-1);

    Select @query='Select '+@sel_cols+','+@full_query_pivot+' into '+@new_table+' From '+(case when @ind_tmpTbl=1 then 'tempdb.' else '' end)+
    @schema+'.'+@table+' Group by '+@sel_cols+';';

    print @query;
    Exec (@query);

End;
GO

这是一个执行示例：

Exec dbo.rs_pivot_table @schema=dbo,@table=##TEMPORAL1,@column=tip_liq,@agg='sum([val_liq]),avg([can_liq]),',@sel_cols='cod_emp,cod_con,tip_liq',@new_table=##TEMPORAL1PVT;

然后Select * From ##TEMPORAL1PVT会返回：

Answer 6

这是上面@Tayrn 答案的修订版，可以帮助您更轻松地理解旋转：

这可能不是执行此操作的最佳方法，但这是帮助我了解如何旋转表格的原因。

ID = 要旋转的行

MY_KEY = 您从原始表中选择的包含要透视的列名的列。

VAL = 要在每列下返回的值。

MAX(VAL) => 可以替换为其他聚合函数。SUM(VAL), MIN(VAL), 等等...

DECLARE @cols AS NVARCHAR(MAX),
@query  AS NVARCHAR(MAX)
select @cols = STUFF((SELECT ',' + QUOTENAME(MY_KEY) 
                from yt
                group by MY_KEY
                order by MY_KEY ASC
        FOR XML PATH(''), TYPE
        ).value('.', 'NVARCHAR(MAX)') 
    ,1,1,'')
set @query = 'SELECT ID,' + @cols + ' from 
         (
            select ID, MY_KEY, VAL 
            from yt
        ) x
        pivot 
        (
            sum(VAL)
            for MY_KEY in (' + @cols + ')
        ) p '

        execute(@query);