如何按月分组统计
我有一表tbdata ,字段有
TLname (nvarchar),TLdate (datetime),TLsum(decimal)分别为名称，写入时间 和数量
一年后运行下来，现在要根据tlname 来分组汇总tlsum ,并且要求按月份进行统计，从一月到12月。如何写呢？


[解决办法]
select TLname,MONTH(TLdate) as TLmonth,SUM(TLsum) TLsum
from tbdata
group by TLname,MONTH(TLdate)
[解决办法]

Create table tbdata (TLname nvarchar(8),TLdate datetime,TLsum decimal)
Insert tbdata
select '第一名','2012-01-01',100  union all 
select '第一名','2012-02-01',600  union all 
select '第二名','2012-03-01',500  union all 
select '第二名','2012-03-01',400  union all 
select '第三名','2012-04-01',200  union all 
select '第四名','2012-05-01',300

select TLname,sum(TLsum) as 数量,month(TLdate) as 月份 from tbdata  group by TLname,month(TLdate) order by TLname

TLname   数量        月份
-------- ------------ -----------
第一名      100         1
第一名      600         2
第三名      200         4
第二名      900         3
第四名      300         5

(5 行受影响)

Create table tbdata (TLname nvarchar(8),TLdate datetime,TLsum decimal)
Insert tbdata
select '张三','2012-01-01',100  union all 
select '李四','2012-02-01',600  union all 
select '张三','2012-03-01',500  union all 
select '李四','2012-03-01',400  union all 
select '李四','2012-04-01',200  union all 
select '张三','2012-05-01',300  union all 
select '张三','2013-01-01',100  union all 
select '李四','2013-02-01',200  union all 
select '张三','2013-03-01',200  union all 
select '李四','2013-03-01',700  union all 
select '李四','2013-04-01',900  union all 
select '张三','2013-05-01',300  

 select year(tldate) as 年份,TLname 
        ,[1]=sum(case when month(tldate)=1 then tlsum else 0 end)
        ,[2]=sum(case when month(tldate)=2 then tlsum else 0 end)
        ,[3]=sum(case when month(tldate)=3 then tlsum else 0 end)
        ,[4]=sum(case when month(tldate)=4 then tlsum else 0 end)
        ,[5]=sum(case when month(tldate)=5 then tlsum else 0 end)
        ,[6]=sum(case when month(tldate)=6 then tlsum else 0 end)
        ,[7]=sum(case when month(tldate)=7 then tlsum else 0 end) 
 
        ,[8]=sum(case when month(tldate)=8 then tlsum else 0 end)
        ,[9]=sum(case when month(tldate)=9 then tlsum else 0 end)
        ,[10]=sum(case when month(tldate)=10 then tlsum else 0 end)
        ,[11]=sum(case when month(tldate)=11 then tlsum else 0 end)
        ,[12]=sum(case when month(tldate)=12 then tlsum else 0 end)
 from tbdata 
 group by year(tldate),TLname

create table #tbdata
(
 tlname nvarchar(50),
 tldate datetime,
 tlsum decimal(18,2)
)

insert into  #tbdata(tlname,tldate,tlsum)
select '张三','2012-06-02','8' union all
select '张三','2012-09-01','10' union all
select '李四','2012-08-01','9' union all
select '王五','2012-08-01','8' union all
select '张三','2012-07-01','6' union all
select '张三','2012-06-01','5' union all
select '李四','2012-06-01','5' 

select tlname,tldate,tlsum from #tbdata



declare @i int 
set @i=1
while @i<=12
begin
select @i as 月份,tlname,sum(tlsum) as tlsum from #tbdata  where @i=month(tldate) group by tlname
    set @i=@i+1
end

drop table #tbdata