在MySQL中，如果想实现将分组之后的多个数据合并到一列，可以使用group_concat函数，如下图所示：
但是，在Sybase中没有这样的函数（别问我为什么使用Sybase，因为公司用的Sybaseo(╯□╰)o）。因为我的Sybase是ASE的，使用变量累计的方法实现了该功能。憋说话，看代码：
IF OBJECT_ID('#test') IS NOT NULL
drop table #test
go
CREATE TABLE #test(
id int null
,comment varchar(100) null
)
GO
insert into #test values(1,'111')
insert into #test values(1,'222')
insert into #test values(1,'333')
insert into #test values(1,'444')
insert into #test values(1,'555')
insert into #test values(1,'666')
insert into #test values(1,'777')
insert into #test values(2,'123')
insert into #test values(2,'456')
insert into #test values(2,'789')
insert into #test values(2,'012')
insert into #test values(2,'345')
insert into #test values(2,'678')
insert into #test values(3,'123')
insert into #test values(3,'456')
insert into #test values(3,'789')
insert into #test values(4,'123')
insert into #test values(4,'456')
insert into #test values(5,'234')
insert into #test values(6,'345')
insert into #test values(7,'789')
GO
BEGIN
declare @cc varchar(500)
declare @cc1 int
declare @num int
set @cc=''
set @num=1
select id,comment,space(500) as sub_comment,0000 as lev into #tt from #test order by id
update #tt
set sub_comment=(case when @cc1=id then @cc || ',' || comment else comment end)
,@cc=(case when @cc1=id then @cc || ',' || comment else comment end)
,lev=(case when @cc1=id then @num+1 else 1 end)
,@num=(case when @cc1=id then @num+1 else 1 end)
,@cc1=id
select t.id,t.sub_comment
from #tt t inner join (select id, max(lev) as tl from #tt group by id) c
on t.id=c.id and t.lev=c.tl
--如果一个分组中的comment多于5个，最多显示5个comment
-- select t.id,t.sub_comment
-- from #tt t inner join (select id, (case when max(lev) > 5 then 5 else max(lev) end) as tl from #tt group by id) c
-- on t.id=c.id and t.lev=c.tl
truncate table #tt
drop table #tt
END