【一对多】查询,求大神帮帮忙。
问题描述:
现在有两个表,tb_1和tb_2
tb_1如下:
IDStrucType
1单板
2Whipple
tb_2如下:
LIDLNameLValue
1靶板1.5
2缓冲屏2.2
2靶板1.8
现在,我想得到结构为Whipple的详细信息,并且得到如下情况:
IDStrucType LName1LValue1 LName2LValue2
2Whipple缓冲屏2.2靶板1.8
[解决办法]
select a.ID,StrucType,LName,LValue,mid=identity(int,1,1) into #tmp from tb_1 a left join tb_2 b on a.id = b.lid where a.id=2 --select * from #tmpselect id,structype, [LName1]=max(case when [mid]='1' then [Lname] else null end), [LValue1]=max(case when [mid]='1' then [LValue] else null end), [LName2]=max(case when [mid]='2' then [Lname] else null end), [LValue2]=max(case when [mid]='2' then [LValue] else null end) from #tmp group by id,structypeGOdrop table #tmp/*id structype LName1 LValue1 LName2 LValue2 ----------- ---------- ---------- ---------- ---------- ---------- 2 Whipple 缓冲屏 2.2 靶板 1.8*/