Mysql 中复制表以及删除冗余数据

从一个表复制到另外一个表

INSERT INTO `zi` SELECT * FROM `hanzi`;

删除冗余数据

DELETE t1 FROM zi t1
INNER JOIN zi t2
WHERE
    t1.id > t2.id AND
    t1._area_id = t2._area_id;

参考地址 http://www.mysqltutorial.org/mysql-delete-duplicate-rows/