mysql 删除表中的某列的重复字段

create table t(
id int not null primary key auto_increment,
name char(10) not null,
sex char(2) not null
)engine=myisam;


insert into t values
(null,‘tom‘,‘男‘),
(null,‘jack‘,‘男‘),
(null,‘小文‘,‘男‘),
(null,‘小文‘,‘女‘),
(null,‘tom‘,‘男‘),
(null,‘小张‘,‘男‘),
(null,‘小赵‘,‘女‘),
(null,‘tom‘,‘男‘),
(null,‘jack‘,‘男‘),
(null,‘小赵‘,‘女‘);

delete t as a
from t as a,
(select * from t group by name having count(1)>1) as b
where a.name=b.name
and a.id > b.id;

select * from t group by name having count(1)>1

select * from t as a,
(select * from t group by name having count(1)>1) as b
where a.name=b.name;

select * from t as a,
(select * from t group by name having count(1)>1) as b
where a.name=b.name
and a.id > b.id;

delete t as a
from t as a,
(select * from t group by name having count(1)>1) as b
where a.name=b.name
and a.id > b.id;