Flask SQL Alchemy – How do I update several records at once through a form

class Item(db.Model):
    id = db.Column(db.Integer, primary_key=True)
    title = db.Column(db.String, nullable=False)

class _SubForm(Form):
    # The HiddenField later contains the id of the data record. 
    id = HiddenField('id')
    excluded = SelectField('Exclude', choices=EXCLUDED_CHOICES, validators=[DataRequired()])

    # The constructor is overwritten in order to bypass further fields for the csrf token. 
    def __init__(self, csrf_enabled=False, *args, **kwargs):
        super(_SubForm, self).__init__(csrf_enabled=csrf_enabled, *args, **kwargs)

class EditForm(FlaskForm):
    items = FieldList(FormField(_SubForm))

@app.route('/edit', methods=['GET', 'POST'])
def edit():
    # Fill in the form with the necessary data. 
    items = Item.query.all()
    form = EditForm(request.form, data={ 'items': items })
    if form.validate_on_submit():
        # Iterate over the FieldList here. 
        for field in form.items.data:
            id = item_field.get('id')
            excluded = item_field.get('excluded')
            print(id, excluded)
    return render_template('edit.html', **locals())

  {{ form.csrf_token }}
  
    {% for field in form.items -%}
    
    {% endfor -%}
  

      

        {{ items[loop.index0].title }}
      
      

        {{ field.hidden_tag() }}
        {{ field.excluded }}