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首页 > 解决方案 > 带有蓝图的 Flask-sqlalchemy - RuntimeError：未找到应用程序。在视图函数中工作或推送应用程序上下文

python - 带有蓝图的 Flask-sqlalchemy - RuntimeError：未找到应用程序。在视图函数中工作或推送应用程序上下文

问题描述

对此有很多问题，但没有一个使用 Flask 蓝图。

我正在尝试使用 sqlite3 查找设置 QuerySelectField。但是我得到了错误：

RuntimeError: No application found. Either work inside a view function or push an application context.

这是我的应用程序结构： 在此处输入图像描述

我的初始化.py

from flask import Flask, render_template, current_app
from flask_mail import Mail
from flask_login import LoginManager
from flask_bootstrap import Bootstrap
from flask_ckeditor import CKEditor
from instance.config import app_config
from app.views.ticket import ticket as ticket_blueprint
from app.views.users import users as user_blueprint
from app.views.main import main as main_blueprint
from app.models import User, db

login_manager = LoginManager()

def page_not_found(e):
    return render_template('404.html'), 404


def register_blueprints_on_app(app):
    app.register_blueprint(user_blueprint)
    app.register_blueprint(ticket_blueprint)
    app.register_blueprint(main_blueprint)


def login_manager_init(app):
    login_manager.login_view = 'users.login'
    login_manager.init_app(app)


# associate id in the cookie with the User object
@login_manager.user_loader
def load_user(user_id):
    print(user_id)
    return User.query.get(user_id)


# application factory
def create_app(config):
    # create application instance
    app = Flask(__name__, instance_relative_config=True)
    app.register_error_handler(404, page_not_found)
    app.config.from_object(app_config[config])
    app.config.from_pyfile('config.py')

    Bootstrap(app)

    mail = Mail()
    mail.init_app(app)
    db.init_app(app)

    ckeditor = CKEditor()
    ckeditor.init_app(app)

    login_manager_init(app)
    register_blueprints_on_app(app)

    return app

这是有问题的forms.py，它位于ticket/views/下

from flask_wtf import FlaskForm
from wtforms import StringField, SubmitField, TextAreaField, FieldList, DateTimeField, SelectField
from wtforms_sqlalchemy.fields import QuerySelectField
from wtforms.fields.html5 import EmailField, TelField
from wtforms.validators import InputRequired, Email
from flask_ckeditor import CKEditorField
from app.models import User


def user_query():
    query = User.query()
    return query


class TicketForm(FlaskForm):
    requested_by = QuerySelectField(label='Requested by',
                                    query_factory=user_query(),
                                    allow_blank=False,
                                    get_label='fullname')
    department = SelectField(label='Department')
    phone = TelField(label='Phone')
    email = EmailField(label='Email', validators=[Email('Enter a valid email address')])
    short_desc = StringField(label='Short Description', validators=[InputRequired('Must enter a short description')])
    description = CKEditorField(label='Description')
    classification = StringField(label='Classification')
    priority = StringField(label='Priority')

    sla_respond_by = DateTimeField(label='Respond by', render_kw={'readonly': True})
    sla_resolve_by = DateTimeField(label='Resolve by', render_kw={'readonly': True})
    sla_status = StringField(label='SLA Status', render_kw={'readonly': True})

    related_tickets = FieldList(StringField(label='Ticker #'))
    client_journal = TextAreaField(label='Client Area')
    work_notes = TextAreaField(label='Work Notes')
    closed_at = DateTimeField(label='Closed')
    closed_by = StringField(label='Closed by')
    followed_by = StringField(label='Followed by')
    submit = SubmitField('Save')

问题部分是当它运行时

 def user_query():
        query = User.query()
        return query

我得到了错误。

对于上下文，这里是票证/视图下的路线文件

from flask import render_template
from app.views.ticket.forms import TicketForm
from flask_login import login_required
from . import ticket


@ticket.get('/ticket')
@ticket.put('/ticket')
@login_required
def ticket():
    form = TicketForm()
    return render_template('ticket.html', form=form)

在票/视图/ init .py

from flask import Blueprint

ticket = Blueprint('ticket', __name__, static_folder='static', template_folder='templates')

from . import routes

我在这里阅读了文档，但没有帮助。https://flask-sqlalchemy.palletsprojects.com/en/2.x/contexts/

我不知道如何传递应用程序上下文，所以这个函数可以工作。

标签： pythonflaskflask-sqlalchemy

解决方案

我通过不在 QuerySelectfield 中使用 query_factory 解决了这个问题。

我从此更改了字段声明：

class TicketForm(FlaskForm):
    requested_by = QuerySelectField(label='Requested by',
                                    query_factory=user_query(),
                                    allow_blank=False,
                                    get_label='full_name')

对此：

class TicketForm(FlaskForm):
    requested_by = QuerySelectField(label='Requested by',
                                    allow_blank=False,
                                    get_label='full_name')

（所以，刚刚删除了 query_factory=user_query()，）

我删除了这个：

def user_query():
        query = User.query()
        return query

然后将此添加到我的蓝图中的路线中：

@ticket.get('/ticket')
@ticket.put('/ticket')
@login_required
def ticket():
    form = TicketForm()

    form.requested_by.query = User.query.all()  # Added this

    print(current_app.app_context())
    return render_template('ticket.html', form=form)

我希望这可以帮助别人，因为它正在做我的头脑。我仍然想知道如何使用 query_factory 以另一种方式做到这一点，因为我确信有办法。所以如果有人知道请分享！

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