例如,我的表设置如下;
course_sections
section_id
course_number
section
term_id
year
professor
capacity
term
term_id
term (Fall, Winter, Spring)
year
我正在尝试的当前查询如下:
SELECT cs.professor as 'Professor Name',t.year as 'Year',t.term as 'Term',sum(cs.capacity) as 'Teaching Capacity'
FROM course_sections cs
JOIN term t ON cs.term_id = t.term_id
GROUP BY cs.professor
ORDER BY cs.professor;
我被困的原因是因为这一次返回了每个老师的姓名,而一个学期的学生能力如下所示。
NAME TERM YEAR STUDENT CAPACITY
Josh Fall 2016 150
Courtney Fall 2016 150
Steve Fall 2016 150
我需要能够这样显示
NAME TERM YEAR STUDENT CAPACITY
Josh Fall 2016 75
Josh Winter 2017 75
Courtney Fall 2016 60
Courtney Winter 2017 80
Steve Fall 2016 100
Steve Winter 2017 50
答案 0 :(得分:0)
您的问题不太清楚,但是根据您的预期输出,您需要
由cs.professor,cs.term_id
获取每学期每位教授的学生人数。