[DB] MySQL删除表中多余的重复记录

删除表中多余的重复记录，重复记录是根据单个字段peopleName来判断，只留有peopleId最小的记录：

delete from people
where peopleName in (select peopleName from people group by peopleName having count(peopleName) > 1)
and peopleId not in (select min(peopleId) from people group by peopleName having count(peopleName) > 1);