MySQL-计算平均值的百分比

我有下表：

平均值

id
subject_id
student_id
value
semester_id

id
class_academic_year_id
student_id

id
class_id
academic_year_id

id
name
academic_year_id
start_date
end_date

班级\u学生

id
subject_id
student_id
value
semester_id

id
class_academic_year_id
student_id

id
class_id
academic_year_id

id
name
academic_year_id
start_date
end_date

课程\学年

id
subject_id
student_id
value
semester_id

id
class_academic_year_id
student_id

id
class_id
academic_year_id

id
name
academic_year_id
start_date
end_date

学期

id
subject_id
student_id
value
semester_id

id
class_academic_year_id
student_id

id
class_id
academic_year_id

id
name
academic_year_id
start_date
end_date

我需要一个查询，以了解某一学年某一学科某一班级学生的毕业百分比（即平均值在5以上的学生的百分比；例如，假设学生的学期平均值为6，学期平均值为7，学期平均值为2，平均值为6.5）

这是当前的查询，但它只返回student_id和两个学期的平均值

select averages.student_id, avg(value) from averages
inner join semesters on semesters.id = averages.semester_id
inner join academic_years on academic_years.id = semesters.academic_year_id

inner join classes_students on classes_students.student_id = averages.student_id
inner join classes_academic_years   on classes_academic_years.id = classes_students.class_academic_year_id

where averages.subject_id = '66' 
and academic_years.id = 3
and classes_academic_years.academic_year_id = academic_years.id
and classes_academic_years.class_id = 259

group by averages.student_id

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我希望结果是74.5%左右。有什么方法可以实现这一点吗？

您应该使用该查询并按类左键联接它

SELECT COUNT(*) FROM classes_students GROUP BY class_academic_year_id ...

这样你就有了COUNT（graded）/COUNT（*），这是一个介于0和1之间的数字，所以你只需要将它乘以100，你就得到了你的百分比