-- 删除多余的重复记录(多个字段)，只保留最小id的记录

DELETE FROM ucms_article WHERE id IN (

    SELECT * FROM (

        SELECT id FROM ucms_article WHERE (title) -- 注意：此处一定要加括号，当成联合字段来处理

        IN (

            -- 查找学号和姓名均重复的学生信息

            SELECT title FROM ucms_article GROUP BY title HAVING COUNT(1) > 1

        ) AND id NOT IN (

            -- 查询最小id的记录

            SELECT MIN(id) FROM ucms_article GROUP BY title HAVING COUNT(1) > 1

        )

    ) AS stu_repeat_copy

);