Joining data from multiple tables using SQLAlchemy

Question

I have three tables in my database:

Links
-----------------------
id | student| class
1 | 2 | 1
2 | 1 | 1
3 | 1 | 2

Student
-----------------------
id | name | age
1 | Bob | 16
2 | Jane | 17

Class
_______________________
id | subject
1 | Math
2 | Science

I want to be able to look at the links table to see what students are in what class and return the results from the student table per class. So, if I were looking at a page that had class information I would get all the students information that are in that class. I want to be able to use Sqlalchemy to make this query, which is what's confusing me since I can't just a straight up JOIN or something.

I'll be passing the class information to the function in Flask, like:

@main.route('/class/<class_id>')
@login_required
def view_class(class_id):

Any help would be appreciated!

Answer 1

You can try this below and since class keyword is reserved in python, you need to use a different column name for Links Table and i have used it below as student_class

@main.route('/class/<class_id>')
@login_required
def view_class(class_id):

    output = session.query(Student).join(Link, Student.id == Link.student).join(Class, Link.student_class == Class.id).filter(Class.id == class_id).all()