查询字段中最小值

来源：互联网发布：全国流动人口大数据编辑：程序博客网时间：2024/05/16 11:29

一 AAA(子编码) BBB(名字)
-----------------------------
A1--------------------------------B1
A1--------------------------------B2
A0--------------------------------B3
A0--------------------------------B4
A0-------------------------------- B5
A2--------------------------------B0
A2-------------------------------- B6
A3--------------------------------B10

结果为下面的

aaa bbb
--------------------------------
A1--------------------------------B1
A0--------------------------------B3
A2--------------------------------B0
A3--------------------------------B10

select aaa,min(bbb) bbb from tb group by aaa

二 AAA              BBB              CCC
-----------------------------------------------
A1                    B1                   0
A1                    B2                   1
A0                    B3                   0
A0                    B4                   1
A0                    B5                   2
A2                    B0                   0
A2                    B6                   1
A3                    B10                 0

结果为下面的

AAA     BBB     CCC
---------------------------------------------------
A1       B1         0
A0       B3         0
A2       B0         0
A3       B10       0

select a.* from tb a, (select AAA,min(CCC)CCC) b where a.CCC = b.CCC and a.AAA = b.AAA