DISTINCT问题
有tb1表
code name
0001 1
0002 2
0001 1
NULL 100
0002 2
0003 3
想得到TB2表
code name
0001 1
0002 2
0003 3
用insert into tb2 (code,name) select DISTINCT code,name from tb1不行，
用insert into tb2 code select DISTINCT code from tb1就可以，但只有一列！
[解决办法]
insert into tb2 (code,name) select code,min(name) from tb1 where code is not null or upper(code)!='NULL'group by code
[解决办法]
insert into tb2 (code,name)
select code,min(name) from tb1 where code is not null group by code,name
