sql语句不知道错在哪

[YXTS122]

insert into student(num,name,age,id)values(11,'three',6,6);
insert into student(num,name,age,id)values(21,'four',6,2);
insert into student(num,name,age,id)values(31,'five',6,1);
insert into student(num,name,age,id)values(41,'six',6,4);
insert into student(num,name,age,id)values(51,'three',7,3);
insert into student(num,name,age,id)values(61,'three',6,8);
insert into student(num,name,age,id)values(71,'five',6,7);
insert into student(num,name,age,id)values(81,'four',6,5);  

[YXTS122]

这样可以，那样不行

[YXTS122]

没人帮忙解答下这个问题么？？？？？？？

[Hello World,]

所说MySQL不支持在更新、删除表的子名中查询本表
可以考虑用临时表/变量

[二月十六]

试试这样

DELETE 
FROM
  student 
WHERE id NOT IN 
  (SELECT 
    Id 
  FROM
    (SELECT 
      MAX(num) id 
    FROM
      student 
    GROUP BY NAME,
      age) t1)