Databases
StackOverflow2013
Postsdbo
POHow I do to update data on many-to-many with WTForms and SQLAlchemy?
 

Note that there are some explanatory texts on larger screens.

plurals
  1. POHow I do to update data on many-to-many with WTForms and SQLAlchemy?
    primarykey
    data
    text
    <p>I've a small problem on my App build with Flask Framework.</p> <p>I'm trying to create a simple User + Permissions module. To archive it, I've a many-to-many relation between Users and Permissions table.</p> <p>Here is my model, form and route</p> <p><strong>Model</strong></p> <pre><code>user_perm = db.Table('user_perm', db.Column('user_id', db.Integer, db.ForeignKey('user.id')), db.Column('perm_id', db.Integer, db.ForeignKey('permissions.id')) ) class User(db.Model): __tablename__ = 'user' id = db.Column(db.Integer, primary_key=True) username = db.Column(db.String(32), unique=True, nullable=False) pwdhash = db.Column(db.String(16), nullable=False) email = db.Column(db.String(128)) permissions = db.relationship('Permission', secondary=user_perm, backref=db.backref('users', lazy='dynamic')) def __init__(self, username, pwdhash, email, perms): self.username = unicode(username) self.pwdhash = pwdhash self.email = email self.permissions = perms def __repr__(self): return '&lt;User {0}&gt;'.format(self.username) class Permission(db.Model): __tablename__ = 'permissions' id = db.Column(db.Integer) perm = db.Column(db.String(50), primary_key=True, unique=True, nullable=False) def __init__(self, perm): self.perm = unicode(perm) def __repr__(self): return '&lt;Permission {0}&gt;'.format(self.perm) </code></pre> <p><strong>Form</strong></p> <pre><code>class AddUser(Form): username = TextField(u'Username', required) pwdhash = TextField(u'Password', required) email = TextField(u'E-email', email_validators) permissions = SelectMultipleField(u'Permissions', required, coerce=int) class EditUser(AddUser): pass </code></pre> <p><strong>Routes</strong></p> <pre><code>@app.route('/admin/user/add', methods=['GET', 'POST']) @login_required def admin_user_add(): form = AddUser(request.form) form.permissions.choices = [(p.id, p.perm) for p in Permission.query.order_by('perm')] if request.method == 'POST' and form.validate(): user = User( form.username.data, form.pwdhash.data, form.email.data, Permission.query.filter(Permission.id.in_(form.permissions.data)).all() ) db.session.add(user) db.session.commit() flash('Successfully added user', category='success') return redirect(url_for('users')) return render_template('admin_user_add.html', form=form) @app.route('/admin/user/edit/&lt;int:user_id&gt;', methods=['GET', 'POST']) @login_required def admin_user_edit(user_id): user = User.query.filter_by(id=user_id).first_or_404() form = EditUser(request.form, obj=user) form.permissions.choices = [(p.id, p.perm) for p in Permission.query.order_by('perm')] form.permissions.data = [p.id for p in user.permissions] if request.method == 'POST' and form.validate(): form.populate_obj(user) user.username = form.username.data user.pwdhash = form.pwdhash.data user.email = form.email.data user.permissions = Permission.query.filter(Permission.id.in_(form.permissions.data)).all() db.session.merge(user) db.session.commit() flash('Successfully updated user', category='success') return redirect(url_for('users')) return render_template('admin_user_add.html', form=form, edit=True) </code></pre> <p>The adding actions works perfectly, the relation are been add, but when I'm trying to edit an user, I get this error.</p> <p><strong>Traceback</strong></p> <pre><code>Traceback (most recent call last): File "/usr/local/lib/python2.7/dist-packages/flask/app.py", line 1518, in __call__ return self.wsgi_app(environ, start_response) File "/usr/local/lib/python2.7/dist-packages/flask/app.py", line 1506, in wsgi_app response = self.make_response(self.handle_exception(e)) File "/usr/local/lib/python2.7/dist-packages/flask/app.py", line 1504, in wsgi_app response = self.full_dispatch_request() File "/usr/local/lib/python2.7/dist-packages/flask/app.py", line 1264, in full_dispatch_request rv = self.handle_user_exception(e) File "/usr/local/lib/python2.7/dist-packages/flask/app.py", line 1262, in full_dispatch_request rv = self.dispatch_request() File "/usr/local/lib/python2.7/dist-packages/flask/app.py", line 1248, in dispatch_request return self.view_functions[rule.endpoint](**req.view_args) File "/var/www/deploy.staging.inovae.ch/webapp/webapp/utilities.py", line 29, in inner return f(*args, **kwargs) File "/var/www/deploy.staging.inovae.ch/webapp/webapp/utilities.py", line 44, in wrapper return f(*args, **kwargs) File "/var/www/deploy.staging.inovae.ch/webapp/webapp/views.py", line 161, in admin_user_edit form.populate_obj(user) File "/usr/local/lib/python2.7/dist-packages/wtforms/form.py", line 73, in populate_obj field.populate_obj(obj, name) File "/usr/local/lib/python2.7/dist-packages/wtforms/fields/core.py", line 283, in populate_obj setattr(obj, name, self.data) File "/usr/local/lib/python2.7/dist-packages/sqlalchemy/orm/attributes.py", line 155, in __set__ instance_dict(instance), value, None) File "/usr/local/lib/python2.7/dist-packages/sqlalchemy/orm/attributes.py", line 892, in set lambda adapter, i: adapter.adapt_like_to_iterable(i)) File "/usr/local/lib/python2.7/dist-packages/sqlalchemy/orm/attributes.py", line 927, in _set_iterable collections.bulk_replace(new_values, old_collection, new_collection) File "/usr/local/lib/python2.7/dist-packages/sqlalchemy/orm/collections.py", line 681, in bulk_replace new_adapter.append_with_event(member) File "/usr/local/lib/python2.7/dist-packages/sqlalchemy/orm/collections.py", line 555, in append_with_event getattr(self._data(), '_sa_appender')(item, _sa_initiator=initiator) File "/usr/local/lib/python2.7/dist-packages/sqlalchemy/orm/collections.py", line 945, in append item = __set(self, item, _sa_initiator) File "/usr/local/lib/python2.7/dist-packages/sqlalchemy/orm/collections.py", line 920, in __set item = getattr(executor, 'fire_append_event')(item, _sa_initiator) File "/usr/local/lib/python2.7/dist-packages/sqlalchemy/orm/collections.py", line 614, in fire_append_event item, initiator) File "/usr/local/lib/python2.7/dist-packages/sqlalchemy/orm/attributes.py", line 800, in fire_append_event value = fn(state, value, initiator or self) File "/usr/local/lib/python2.7/dist-packages/sqlalchemy/orm/unitofwork.py", line 35, in append item_state = attributes.instance_state(item) AttributeError: 'long' object has no attribute '_sa_instance_state' </code></pre>
    singulars
    1. PO
      singulars
      1. PTAnswer
    1. This table or related slice is empty.
    1. PTQuestion
    1. This table or related slice is empty.
    1. USyvan
    plurals
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. PO
      singulars
      1. PTAnswer
    2. PO
      singulars
      1. PTAnswer
    1. VO
      singulars
      1. POHow I do to update data on many-to-many with WTForms and SQLAlchemy?
      1. This table or related slice is empty.
      1. VTUpMod
    2. VO
      singulars
      1. POHow I do to update data on many-to-many with WTForms and SQLAlchemy?
      1. This table or related slice is empty.
      1. VTUpMod
    3. VO
      singulars
      1. POHow I do to update data on many-to-many with WTForms and SQLAlchemy?
      1. This table or related slice is empty.
      1. VTUpMod
    1. This table or related slice is empty.
 

Querying!

 
Guidance
A row detail

Detail views are divided into sections. All the information in the data section comes from columns in the selected row. The other sections display data from other, related rows.

Related data can be related in a to-one or a to-many fashion. Captions of data related in a to-many fashion link to a list view showing a filtered view of the table.

Try moving around until you find a non-empty to-many entry and click on the label to get to one. You can move back to the root by clicking on the database name in the header.

SQuiL has stopped working due to an internal error.

If you are curious you may find further information in the browser console, which is accessible through the devtools (F12).

Reload