使用flask-sqlalchemy访问相关记录

Question

I am trying to access all related records using flask-sqlalchemy.

My model class' have the following structure:

class User(db.Model):
    id = db.Column(db.Integer, primary_key=True)
    name = db.Column(db.String(64), index=True, nullable=False)
    posts = db.relationship('Post', backref='author', lazy='dynamic')

    def __repr__(self):
        return f'<User {self.name}>'


class Post(db.Model):
    id = db.Column(db.Integer, primary_key=True)
    title = db.Column(db.String(64), index=True, nullable=False)
    date_posted = db.Column(db.DateTime, index=True, default=datetime.utcnow)
    department_id = db.Column(db.Integer, db.ForeignKey('user.id'))

    def __repr__(self):
        return f'<Post {self.title}>'

I would like to access Post information related to a particular User; The following template is passed a copy of the Users record.

{% if users %}
<p>USERS</p>
    <ul>
        {% for user in users %}
            <li> {{ user.id }}</li>
            <li> {{ user.name }}</li>

        {% for post in user.posts %}
            <li>{{ post.title }} </li>
        {% endfor %}

        {% endfor %}
    </ul>
{% endif %}

Do I need to create some kind of dict to map posts to their uers before passing the values to the template?

I appreciate the simplicity of this question, I am an absolute beginner. Any help would be very much appreciated.

Answer 1

What is in your template looks right, you now just need to pass the users to the template.

@app.route('/posts', methods=['GET'])
def posts():
    users = User.query.all()
    return render_template('your_template.html', users=users)

so now your {%for user in users%} in the template refers to the queried users with the loaded relationships (hoping you have your models.py, your app.py (where the above code is) with the relevant imports and template).

hope that helps