ERROR가 "그룹 함수가 너무 깊이 중첩되어 있습니다"?

Question

은 학생 수가 가장 적은학과의 이름을 표시하려고했습니다. 테이블 구조가

SELECT department_name 
FROM department natural join student 
GROUP BY department_name 
HAVING MIN(COUNT(*)); 

처럼 =>

Answer 1

이 같은 것을보십시오 :

SELECT TOP 1 department_name, count(*) AS number_of_students 
FROM department natural join student 
GROUP BY department_name 
ORDER BY number_of_students 

그것은 당신에게 학생들의 숫자로 정렬 된 부서의 목록을 제공합니다 . TOP 1을 통해 첫 번째 행만 선택하면 학생 수가 가장 적은 부서 만 받게됩니다.

Answer 2

이렇게하면 어떨까요?

SELECT 
T1.department_name, COUNT(T2.department_id) totalCount 
FROM department T1 
LEFT JOIN student T2 
ON T1.department_id = T2.department_id 
GROUP BY T2.department_id 
HAVING COUNT(T2.department_id) = 
(
    SELECT 
    COUNT(T2.department_id) totalCount 
    FROM department T1 
    LEFT JOIN student T2 
    ON T1.department_id = T2.department_id 
    GROUP BY T2.department_id 
    ORDER BY totalCount ASC 
    LIMIT 1 
) 

SQLFIDDLE DEMO