DELETE consum_recordFROM consum_record, ( SELECT min(id) id, user_id, monetary, consume_time FROM consum_record GROUP BY user_id, monetary, consume_time HAVING count(*) > 1 ) t2WHERE consum_record.user_id = t2.user_id and consum_record.monetary = t2.monetary and consum_record.consume_time = t2.consume_timeAND consum_record.id > t2.id;上面这条sql语句，仔细看一下，揣摩出思路也不难，大概也分为3步来理解：
(SELECT min(id) id, user_id, monetary, consume_time FROM consum_record GROUP BY user_id, monetary, consume_time HAVING count(*) > 1 ) t2 查询出重复记录形成一个集合（临时表t2），集合里是每种重复记录的最小ID
consum_record.user_id = t2.user_id and consum_record.monetary = t2.monetary and consum_record.consume_time = t2.consume_time 关联 判断重复基准的字段
根据条件，删除原表中id大于t2中id的记录
看到这个语句的时候，心里想这也太厉害了。这么一个简单的sql语句，竟然可以解决这么复杂的问题，涨姿势了~
原文：https://www.cnblogs.com/php-no-2/p/12132545.html