How to display data from linked tables in Flask using the SQLAlchemy library?

Question

Flask

How to pull data from related tables in Flask here is the model code

class Session_cinema(db.Model):
    id = db.Column(db.Integer, primary_key=True)
    film_id = db.Column(db.Integer(), db.ForeignKey('film.id'))
    time = db.Column(db.DateTime)
    data = db.Column(db.DateTime)
    hall = db.Column(db.String(100))
    session_price = db.Column(db.Integer())

    def __init__(self, time, data, hall, session_price):
        self.time = time
        self.data = data
        self.hall = hall
        self.session_price = session_price

ForeignKey links this table to another table here is the code of this model

class Film(db.Model):
    id = db.Column(db.Integer(), primary_key = True)
    name = db.Column(db.String(80))
    description = db.Column(db.String(255))
    cast = db.Column(db.String(80))
    genre = db.Column(db.String(15))
    length = db.Column(db.Integer())
    ageRestriction = db.Column(db.Integer())

    def __init__(self, name, description,cast, genre, length, ageRestriction):
        self.name = name
        self.description = description
        self.cast = cast
        self.genre = genre
        self.length = length
        self.ageRestriction = ageRestriction

we need to display the data from the film table the name of the film. Here is the code that sends a list of data from the Session_cinema table

@app.route('/session/list', methods=['POST', 'GET'])
def session_list():
    return render_template('session_list.html', items=Session_cinema.query.all())

HTML

<tbody>
                        {% for item in items %}
                        <tr>
                            <td>{{ item.time }}</td>
                            <td>{{ item.data }}</td>
                            <td>{{ item.hall }}</td>
                            <td>{{ item.session_price }}</td>
                        </tr>
                        {% endfor %}
                    </tbody>

there before time should be the name of the movie.

Answer 1

Define a relationship with Film in the Session_cinema model

class Session_cinema(db.Model):
    film_id = db.Column(db.Integer(), db.ForeignKey('film.id'))
    ...
    film = relationship('Film')

Then it will be possible to write in the template
<td>{{ item.film.name }}</td>