更新时间:2022-02-19 23:12:23
在你的表上添加唯一索引:
ALTER IGNORE TABLE `TableA`
ADD UNIQUE INDEX (`member_id`, `quiz_num`, `question_num`, `answer_num`);
另一种方法是:
在您的表中添加主键,然后您可以使用以下查询轻松地从表中删除重复项:
Add primary key in your table then you can easily remove duplicates from your table using the following query:
DELETE FROM member
WHERE id IN (SELECT *
FROM (SELECT id FROM member
GROUP BY member_id, quiz_num, question_num, answer_num HAVING (COUNT(*) > 1)
) AS A
);