1. 查询重复数据：

2. 脚本如下：

DELETE from 表 WHERE (字段) IN ( SELECT 字段 FROM 表 GROUP BY 字段 HAVING COUNT(字段) > 1) AND ROWID NOT IN (SELECT MIN(ROWID) FROM 表 GROUP BY 字段 HAVING COUNT(*) > 1);

3.修改脚本：

 DELETE from card_imp

 WHERE (cardno) IN (SELECT cardno FROM card_imp GROUP BY cardno HAVING COUNT(cardno) > 1)

   AND ROWID NOT IN

       (SELECT MIN(ROWID) FROM card_imp GROUP BY cardno HAVING COUNT(*) > 1);

4.查询结果：