Accessing extra data in a sqlalchemy associated object

问题

The User object can be involved with a Project in many different ways, specified by Job association table. In my template file, I'm trying to loop through all of the projects in current_user.projects and with each one, specify what the Job was for that user in that project... but I can't get the syntax right.

MODELS

class Project(db.Model):
    id = db.Column(db.Integer(), primary_key=True)
    title = db.Column(db.String(80))
    users = db.relationship("Job", back_populates="project")

class User(db.Model, UserMixin):
    id = db.Column(db.Integer, primary_key=True)
    first_name = db.Column(db.String(155))
    last_name = db.Column(db.String(155))
    email = db.Column(db.String(255), unique=True)
    password = db.Column(db.String(255))
    projects = db.relationship("Job", back_populates="user")

# defines a user's role related to each assigned project
class Job(db.Model):
    __tablename__ = 'job'
    user_id = db.Column(db.Integer, db.ForeignKey('user.id'), primary_key=True)
    project_id = db.Column(db.Integer, db.ForeignKey('project.id'), primary_key=True)
    job = db.Column(db.String(50))
    user = db.relationship("User", back_populates="projects")
    project = db.relationship("Project", back_populates="users")

    def __init__(self, user_id, project_id, job="client"):
        self.user_id = user_id
        self.project_id = project_id
        self.job = job

VIEW

@app.route('/projects')
@login_required
def projects():
    projects = Project.query.join(Job).filter_by(user_id=current_user.id).all() 
    # current_user.projects would probably do the same thing            
    return render_template('project/projects.html', projects=projects)

TEMPLATE

<div class="accordion style-two gradient-bg">
    <div class="panel-group" id="accordion-2">
        {% for project in projects %}
        <div class="panel panel-default">
            <!-- Accordian Title -->
            <div class="panel-heading">
                <div class="panel-title">
                    <a class="accordion-toggle collapsed" href="#{{ project.id }}" data-parent="#accordion-2" data-toggle="collapse" aria-expanded="false">
                        {{ project }} - HELP NEEDED HERE--> ({{ project.user[0].job }})
                    </a>
                </div>
            </div>
            <!-- Accordian Detail -->
            <div id="{{ project.id }}" class="panel-collapse collapse">
                <div class="panel-body">
                    <div class="container">
                        <div class="row">
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                        </div>
                    </div>
                </div>
            </div>
        </div>
        {% endfor %}
   </div>
</div>

As shown above, I have project.users[0].job which will show the correct information because I have just one user in the system. How can I specify on the template level that I'm looking for the job associated with the the current_user as I'm looping through projects? Thanks!

回答1:

As suggested in the comments, the easiest way is to simply query the associated table to begin with: projects = Job.query.filter_by(user_id=current_user.id).all()

I have ready access to each Project referenced (project.project) and can also get the details of the job (project.job).

来源：https://stackoverflow.com/questions/44875204/accessing-extra-data-in-a-sqlalchemy-associated-object

标签

python

Flask

sqlalchemy

flask-sqlalchemy

associated-object