generating drop down list of users in database using wtforms and sqlalchemy

I am trying to generate a drop down list of all the users in my database so I can assign admins later that can edit their information. I keep getting the following error from my template:

AttributeError: 'QueryAllUsers' object has no attribute '_fields'

views.py

@app.route('/mobility_add_users', methods=['GET', 'POST'])
@login_required
def mobility_add_users():
    #users=User.query.all()
    form=QueryAllUsers(request.form)
    return render_template('mobility_add_users.html',title='Mobility Add Users', form=form)

forms.py

class QueryAllUsers(Form):
    print("In QueryAll")
    #users=User.query.all()
    user_list = SelectField(u'Choose')

    def __init__(self, *args, **kwargs):
        self.user_list.choices=[(obj.id, obj.username) for obj in User.query.order_by('username')]
    print("Query all done")

models.py

class User(db.Model):
    id = db.Column(db.Integer, primary_key=True)
    username = db.Column(db.String(32), index=True, unique=True)
    password_hash = db.Column(db.String(128))
    email = db.Column(db.String(120), index=True, unique=True)
    posts = db.relationship('Post', backref='author', lazy='dynamic')
    #mobilitys = db.relationship('Mobility', backref='username', lazy='dynamic')
    about_me = db.Column(db.String(140))
    last_seen = db.Column(db.DateTime)

mobility_add_users.html

<!-- extend base layout -->
{% extends "base.html" %}

{% block content %}
    {% from "_formhelpers.html" import render_field %}
    <form method=post>
      <dl>
            {{ form.hidden_tag() }}
        {{ render_field(form.query) }}
      </dl>
      <p><input type=submit value=Register></p>
    </form>
{% endblock %}

More of the error readback

File "/home/jsnyder10/Documents/45/app/templates/mobility_add_users.html", line 8, in block "content"

{{ form.hidden_tag() }}

File "/home/jsnyder10/Documents/45/flask/lib/python2.7/site-packages/flask_wtf/form.py", line 135, in hidden_tag

u'n'.join(text_type(f) for f in hidden_fields(fields or self))

File "/home/jsnyder10/Documents/45/flask/lib/python2.7/site-packages/flask_wtf/form.py", line 135, in <genexpr>

u'n'.join(text_type(f) for f in hidden_fields(fields or self))

File "/home/jsnyder10/Documents/45/flask/lib/python2.7/site-packages/flask_wtf/form.py", line 125, in hidden_fields

for f in fields:

File "/home/jsnyder10/Documents/45/flask/lib/python2.7/site-packages/wtforms/form.py", line 57, in __iter__

return iter(itervalues(self._fields))

I’m still new to this so please go easy on me.

Answer

Hope this helps.

from wtforms.ext.sqlalchemy.fields import QuerySelectField


class QueryAllUsers(Form):
    user_list = QuerySelectField(
        'Choose',
        query_factory=lambda: User.query, // you can add order_by(I am not sure)
        allow_blank=False
    )


class User(db.Model):
    // add below lines to your model. you can refactor this as per your need.
    def __repr__(self):
        return "<User(id='%s', name='%s')>" % (self.id, self.name)