Question

我不知道我在做错什么，因为与其他示例一样，但是我正在尝试使用一种形式将新的航班添加到sql数据库并将其显示在html页面上，现在当我尝试发布形式，我收到此错误ValueError：词典更新序列元素＃0的长度为1；需要2个

这是表单类：

class NewFlight(FlaskForm):

    flight_number = IntegerField('Flight Number', validators=[DataRequired()])

    date = StringField('Departure date', validators=[DataRequired()])

    picture = FileField('Upload Cover Image', validators=[FileAllowed(['jpg', 'png'])])

    destination = StringField('Destination Airport', validators=[DataRequired()])

    fly_from = StringField('Departure Location', validators=[DataRequired()])

    price = IntegerField('Price', validators=[DataRequired()])

    submit = SubmitField('Add Flight')

和用于SQL的模型类：

class CurrentFlights(db.Model):
    id = db.Column(db.Integer, primary_key=True)
    flight_number = db.Column(db.Integer, unique=True, nullable=False)
    date = db.Column(db.String(100), nullable=False)
    image = db.Column(db.String(20), nullable=False, default='plane.jpg')
    destination = db.Column(db.String(100), nullable=False)
    fly_from = db.Column(db.String(100), nullable=False)
    price = db.Column(db.Integer, nullable=False)

和路线部分：

@app.route('/add_flight', methods=['GET', 'POST'])
def add_flight():
    form = NewFlight()
    if form.validate_on_submit():
        flight = NewFlight(flight_number=form.flight_number.data, data=form.date.data, image=form.picture.data, destination=form.destination.data, fly_from=form.fly_from.data, price=form.price.data)
        db.session.add(flight)
        db.session.commit()
        flash('New Flight added to database!', 'success')
        return redirect(url_for('home'))
    return render_template('admin_AddFlights.html', title='Add New Flight', form=form)

这可能是一个愚蠢的错误，但是可以得到任何帮助，

谢谢！

回溯：

C:\Users\CarlSecondAccount\PycharmProjects\flight_tracker\pythonmain\lib\site-packages\flask_sqlalchemy\__init__.py:794: FSADeprecationWarning: SQLALCHEMY_TRACK_MODIFICATIONS adds significant overhead and will be disabled by default in the future.  Set it to True or False to suppress this warning.
  'SQLALCHEMY_TRACK_MODIFICATIONS adds significant overhead and '
 * Running on http://127.0.0.1:5000/ (Press CTRL+C to quit)
127.0.0.1 - - [06/Feb/2019 22:49:12] "GET / HTTP/1.1" 200 -
127.0.0.1 - - [06/Feb/2019 22:49:15] "GET /login HTTP/1.1" 200 -
127.0.0.1 - - [06/Feb/2019 22:49:16] "GET /admin_menu HTTP/1.1" 200 -
127.0.0.1 - - [06/Feb/2019 22:49:20] "GET /admin_menu HTTP/1.1" 200 -
127.0.0.1 - - [06/Feb/2019 22:49:38] "POST /admin_menu HTTP/1.1" 302 -
127.0.0.1 - - [06/Feb/2019 22:49:38] "GET /admin_home HTTP/1.1" 200 -
127.0.0.1 - - [06/Feb/2019 22:49:58] "GET /add_flight HTTP/1.1" 200 -
[2019-02-06 22:50:15,100] ERROR in app: Exception on /add_flight [POST]
Traceback (most recent call last):
  File "C:\Users\CarlSecondAccount\PycharmProjects\flight_tracker\pythonmain\lib\site-packages\flask\app.py", line 2292, in wsgi_app
    response = self.full_dispatch_request()
  File "C:\Users\CarlSecondAccount\PycharmProjects\flight_tracker\pythonmain\lib\site-packages\flask\app.py", line 1815, in full_dispatch_request
    rv = self.handle_user_exception(e)
  File "C:\Users\CarlSecondAccount\PycharmProjects\flight_tracker\pythonmain\lib\site-packages\flask\app.py", line 1718, in handle_user_exception
    reraise(exc_type, exc_value, tb)
  File "C:\Users\CarlSecondAccount\PycharmProjects\flight_tracker\pythonmain\lib\site-packages\flask\_compat.py", line 35, in reraise
    raise value
  File "C:\Users\CarlSecondAccount\PycharmProjects\flight_tracker\pythonmain\lib\site-packages\flask\app.py", line 1813, in full_dispatch_request
    rv = self.dispatch_request()
  File "C:\Users\CarlSecondAccount\PycharmProjects\flight_tracker\pythonmain\lib\site-packages\flask\app.py", line 1799, in dispatch_request
    return self.view_functions[rule.endpoint](**req.view_args)
  File "C:\Users\CarlSecondAccount\PycharmProjects\flight_tracker\flight\routes.py", line 118, in add_flight
    flight = NewFlight(flight_number=form.flight_number.data, data=form.date.data, image=form.picture.data, destination=form.destination.data, fly_from=form.fly_from.data, price=form.price.data)
  File "C:\Users\CarlSecondAccount\PycharmProjects\flight_tracker\pythonmain\lib\site-packages\wtforms\form.py", line 212, in __call__
    return type.__call__(cls, *args, **kwargs)
  File "C:\Users\CarlSecondAccount\PycharmProjects\flight_tracker\pythonmain\lib\site-packages\flask_wtf\form.py", line 88, in __init__
    super(FlaskForm, self).__init__(formdata=formdata, **kwargs)
  File "C:\Users\CarlSecondAccount\PycharmProjects\flight_tracker\pythonmain\lib\site-packages\wtforms\form.py", line 278, in __init__
    self.process(formdata, obj, data=data, **kwargs)
  File "C:\Users\CarlSecondAccount\PycharmProjects\flight_tracker\pythonmain\lib\site-packages\wtforms\form.py", line 124, in process
    kwargs = dict(data, **kwargs)
ValueError: dictionary update sequence element #0 has length 1; 2 is required
127.0.0.1 - - [06/Feb/2019 22:50:15] "POST /add_flight HTTP/1.1" 500

Answer 1

从事物的外观来看，您需要更改此行

flight = NewFlight(
    flight_number=form.flight_number.data, 
    data=form.date.data, 
    image=form.picture.data, 
    destination=form.destination.data, 
    fly_from=form.fly_from.data, 
    price=form.price.data)

对此

flight = CurrentFlights(
    flight_number=form.flight_number.data, 
    data=form.date.data, 
    image=form.picture.data, 
    destination=form.destination.data, 
    fly_from=form.fly_from.data, 
    price=form.price.data)

因为NewFlight用于初始化表单，而CurrentFlights用于初始化数据库模型

FLASK-ValueError：字典更新序列元素＃0的长度为1；需要2个

1 个答案: