MySQL选择使用组和计数连接表

Question

For my project, I've a student table and a school table.

A student belongs to a company. A school has many students.

(A student's school_id is assigned NULL when that student graduates.)

The student table:
+----+------------+-----------+------------+
| id | first_name | last_name | school_id  |
+----+------------+-----------+------------+
The school table:
+----+------------+------------------------+
| id | city_id    | name                   |
+----+------------+------------------------+

The goal is to inner join these tables, count the students for each school, and order by the student number.

Answer 1

Consider following SQL query:

SELECT school.NAME, 
       count(student.id) AS Total_Student 
FROM   school 
       LEFT JOIN student 
              ON school.id = student.school_id 
GROUP BY school.id
ORDER BY Total_Student