SQL---查找+删除重复记录

查找重复记录：

1，重复记录根据单个字段来判断

SELECT peopleId
FROM people
GROUP BY peopleId
HAVING COUNT(peopleId) > 1

2，重复记录根据多个字段来判断

SELECT peopleId, seq
FROM people
GROUP BY peopleId, seq
HAVING COUNT(*) > 1

删除重复记录：

删除peopeId重复的记录，只保留最小的id对应的记录：

DELETE FROM people
WHERE id NOT IN (SELECT MIN(id) FROM people
                 GROUP BY peopleId)