Hi I have a tables like this
exams

id | exam_name
1  | computer science
2  | Environment science

exam_students

id | exam_id | student_name
1  | 1       | Josh
2  | 1       | Michael
3  | 1       | John

I just need to join and count the total students of each exam and output something like this

exam_name          | total_students |
computer science   | 3              |
Environment science| 0              |

Thank you for your any help and suggestions