我在想想..

Question

mysql> select * from student;
+-----+------+-------+-------+
| sid | name | calss | score |
+-----+------+-------+-------+
|   1 | 张三     | php班   |    57 |
|   2 | 李四     | asp班   |    59 |
|   3 | 王五     | net班   |    59 |
|   4 | 小倩   | asp班   |    58 |
|   5 | 小张    | php班   |    98 |
|   6 | 小陈    | net班   |    66 |
|   7 | 小李    | htm班   |    78 |
|   8 | 小王    | php班   |    45 |
+-----+------+-------+-------+
查询各个班不及格的学生与及格的学生

Answer 1

select class,sum(if(score < 60,1,0)) as '不及格',sum(if(score >=60,1,0)) as '及格' from student group by class

Answer 2

试了你的  结果有点问题，
+-------+--------+------+
| calss | 不及格       | 及格     |
+-------+--------+------+
| asp班   |      2 |    0 |
| htm班   |      0 |    1 |
| net班   |      1 |    1 |
| php班   |      2 |    1 |
+-------+--------+------+

Answer 3

查询各个班不及格的学生与及格的学生?
人数还是啥?
人数的话,上面的sql木有什么问题啊,

Answer 4

select class,count(case when score>=60 then 1 else 0 end) ,count(case when score<60 then 1 else 0 end)
from student
group by class