jialan75的博客

mysql 安装 ent\mysql-5.7.19\data port=3306 skip-grant-tabl

delete from htorder where id not in ( select t.max_id from (select min(id) as max_id from htorder group by htCode,name1,orderDate) as t ); 删除表中(htCode,name1,orderDate)这三个字段 重复的数据 并且 保留第一个插入的数据 ...