UC知道三表SQL查询题目求解
来源：百度知道 编辑：UC知道 时间：2024/09/24 06:18:33
student：stu_no，stu_name，entrance_math(入学数学)，class_no
class：class_no，class_name，teacher_no
teacher：teacher_no，teacher_name，teacher_major(教师专业)
1. 显示所有入学数学平均分及格的班级的班级号与入学数学平均分。
2. 显示所有同学的班主任是谁
3. 显示班级的班级名，教师名，教师专业为计算机的
请大家帮忙写出前2题的sql语句啊，谢谢了！感激不尽。尽快
class：class_no，class_name，teacher_no
teacher：teacher_no，teacher_name，teacher_major(教师专业)
1. 显示所有入学数学平均分及格的班级的班级号与入学数学平均分。
2. 显示所有同学的班主任是谁
3. 显示班级的班级名，教师名，教师专业为计算机的
请大家帮忙写出前2题的sql语句啊，谢谢了！感激不尽。尽快
1:
select a.class_no, a.classname,avg(b.entrance_math) as avg_math
from class a , student b
where a.class_no = b.class_no
group by a.class_no, a.classname
Having avg(b.entrance_math) >= 60
2:
select b.stu_no, b.stuname, c.teacher_name
from class a , student b , teacher c
where a.class_no = b.class_no
And a.teacher_no = c.teacher_no
order by b.stu_no
3:
select a.class_no, a.class_name, c.teacher_name, c.teacher_major
from class a , teacher c
where a.teacher_no = c.teacher_no
and teacher_major = '计算机'