MySQL查询重复字段,重复记录的方法

如果仅仅是查找数据库中name不重复的字段:
SELECT `name` FROM `table` GROUP BY `name`;

查询哪些字段是重复:
SELECT `name`,count(`name`) as count FROM `table` GROUP BY `name` HAVING count(`name`) >1 ORDER BY count DESC;

查找表中的重复记录，重复记录是根据单个字段（peopleId）来判断
select * from people
where peopleId in (select peopleId from people group by peopleId having count(peopleId) > 1)