如何删除mysql中的唯一记录？

我有一张这样的桌子

rowID | StudentName | rollNo | Class
      |             |        |
1     | ABC         |10      |  5   
2     | ABC         |10      |  5
3     | xyz         |11      |  5
4     | asd         |12      |  5

如何删除类为

5

这样我就有剩下的表了

rowID | StudentName | rollNo | Class
      |             |        |
1     | ABC         |10      |  5  

---

我想这正是你想要的：

select min(id), StudentName, rollNo, Class
from t
where class = 5
group by StudentName, rollNo, Class
having count(*) > 1;

如果确实要删除记录，则需要使用

delete

：

delete t
    from t left join
         (select studentname, rollno, class, min(id) as min_id, count(*) as cnt
          from t
          group by studentname, rollno, class
         ) tt
         on t.id = tt.minid and tt.cnt > 1
    where tt.minid is null;

试试这个

DELETE t1 FROM table t1
        INNER JOIN
    table t2 
WHERE
    t1.rowID < t2.rowID AND t1.StudentName = t2.StudentName and t1.rollNo=t2.rollNo

从表t1中删除t1
内连接
表t2
哪里
t1.rowID

这将删除所有重复的行，留下具有最高

rowID