加一列自增主键alter table tb add int not null auto_increment primary key;select *
from tb A
where not exists(select 1 from tb A.type=type and A.name1=name1 and A.name2=name2 and A.id>id);
from tb A
where not exists(select 1 from tb A.type=type and A.name1=name1 and A.name2=name2 and A.id>id);
from 始表格
group by name1,name2
我修改后可用的完整代码是:
alter table tb ADD ID INT UNSIGNED not null auto_increment,ADD primary key(ID);
select *
from tb A
where not exists(select 1 from tb WHERE A.type=type and A.name1=name2 and A.name2=name1 and A.ID>ID);
目前还在理解消化中