如何从另一个表中列的值最多的表中获取行？

Question

我需要做的是我需要从一个表中获取行，其中另一个表中的列中的某个值最多。以下是2个表格的结构：

 --------------------------------------------
 |schoolid|schoolname|schoolstate|schoolcity|
 --------------------------------------------
 |  1     | school a | New York  | New York |
 |  2     | school b | California|Las Angeles|
 |  3     | school c | Texas     | Dallas   |
 --------------------------------------------

 -----------------------------------------
 |studentid|studentname|studentschool|gpa|
 -----------------------------------------
 |  1      | John Doe  | school a    |3.1|
 |  2      | John Doe  | school c    |1.7|
 |  3      | John Doe  | school b    |2.8|
 |  4      | John Doe  | school a    |3.9|
 |  5      | John Doe  | school a    |3.0|
 -----------------------------------------

要重新提出问题，我需要根据每所学校的学生数量选择和订购学校。

Answer 1

您可以使用

select s.schoolname, (select count(s1.schoolid) from school s1 ,students st1 
 where    s1.schoolname=st1.studentschool and st1.studentschool=s.schoolname) 
studentCount from school s order by studentCount  desc;

或者您可以使用（如果您不需要上学没有学生）

select s1.schoolname,count(*)studentcount  from school s1 ,students st1 
where s1.schoolname=st1.studentschool GROUP BY s1.schoolname order by  studentcount desc;