表数据如下
Field1 Field2
A01 Y
A01 N
A02 Y
A03 N
要得到结果:
Field1 Field2
A01 N
A02 Y
A03 N
求最简单SQL
说明:
记录如果唯一,就直接取Field2的值,如果不唯一,就赋'N'
Field1 Field2
A01 Y
A01 N
A02 Y
A03 N
要得到结果:
Field1 Field2
A01 N
A02 Y
A03 N
求最简单SQL
说明:
记录如果唯一,就直接取Field2的值,如果不唯一,就赋'N'
from tbl group by Field1
from tbl group by Field1
from tb
group by Field1不知够简单不哦
from tbl group by Field1
create table #t(Field1 varchar(100), Field2 varchar(100))insert into #t
select 'A01','Y' union all
select 'A01','N' union all
select 'A02','Y' union all
select 'A03','N'select Field1,case when count(*)>1 then 'N' else min(Field2) end as Field2
from #t a
group by Field1drop table #t/*
A01 N
A02 Y
A03 N*/
select Field1,Field2=(case when count(*)>1 then 'N' else Field2 end)
from tbl group by Field1