Sql Server：多行合并成一行，并做分组统计的两个方法

复制代码 代码如下:

–创建 test 表 ，插入数据

CREATE TABLE test(code varchar(50), [values] varchar(10),[count] int)

INSERT test SELECT ‘001’, ‘aa’,1

UNION ALL SELECT ‘001’, ‘bb’,2

UNION ALL SELECT ‘002’, ‘aaa’,4

UNION ALL SELECT ‘002’, ‘bbb’,5

UNION ALL SELECT ‘002’, ‘ccc’,3;

–方法一

–将多行合并成一行，并做分组统计

SELECT code,

       [values] =

       stuff(b.[values].value(‘/R[1]’, ‘nvarchar(max)’),

,

,

             ”),[count]

  FROM (SELECT  code,sum([count]) as [count]

          FROM test

         GROUP BY code) a

 CROSS apply (

        SELECT [values] =(

            SELECT N’,’ + [values] FROM test

              WHERE code = a.code

                         FOR XML PATH(”), ROOT(‘R’), TYPE

        )

) b;

–方法二

—SQL2005中的新解法   使用XML

SELECT code, data=STUFF((SELECT ‘,’+[values] FROM test t WHERE code=t1.code FOR XML PATH(”)), 1, 1, ”),sum([count]) as [count]

FROM test t1

GROUP BY code

–查询结果

–001    aa,bb    3

–002    aaa,bbb,ccc    12

drop table test