从 Flask 蓝图访问数据库

Question

我正在使用 Flask 和 SQLAlchemy 构建一个 RESTful API 应用程序，并尝试应用蓝图模式来注册我的路由。蓝图@route 函数包含对数据库会话对象的引用。我希望以“代理方式”访问它 - 以一种您可以使用 app.current_app 访问 Flask.app 的方式，但我的实现不起作用。

wsgi.py：（运行来自这里）

# imports
from wallet.walletapp import main

app = create_app(url='sqlite:///./test.db')
dbase = Database(url='sqlite:///./test.db')

db = dbase.create_session()
models.Base.metadata.create_all(bind=dbase.engine)

abort = Abort(app, db)
app.config['database'] = db
app.config['abortion'] = abort
with app.app_context:
    app.register_blueprint(main)
app.run(debug=True)

walletapp.py

main = Blueprint('main', __name__)
app = current_app
db = current_app.config['database']
abort = current_app.config['abortion']

# Get wallet list
@main.route('/v1/wallets', methods=['GET'])
def get_wallets():
    '''
    Get all the wallets and their balances
    '''
    wallets = db.query(models.Wallet).all()
    result = wallets_schema.dump(wallets)

    resp = cook_response(app, {'wallets': result})

    return resp, 200

这样我得到一个 RuntimeError: Working out of application context early - 在 wsgi.py:

的导入阶段

  File "/wsgi.py", line 5, in <module>
        from wallet.walletapp import main
  File "/walletapp.py", line 26, in <module>
        db = current_app.config['database']
  File "/env/lib/python3.9/site-packages/werkzeug/local.py", line 422, in __get__
        obj = instance._get_current_object()
  File "/env/lib/python3.9/site-packages/werkzeug/local.py", line 544, in _get_current_object
        return self.__local()  # type: ignore
  File "env/lib/python3.9/site-packages/flask/globals.py", line 47, in _find_app
        raise RuntimeError(_app_ctx_err_msg)

这背后的想法是使 walletapp.py 作为真正的蓝图更加灵活：例如，在单元测试中轻松地将工作数据库交换为虚拟数据库。

总结：

Defining or importing database (db) inside walletapp.py makes module unpluggable: I can work only with database imported or stated in it. How can I rewrite my code to make it working as expected?

This question has a direct connection with mine, but answers give not mush: use Flask-SQLAlchemy or "declare the database object before the context and then import it", which I tried to implement here. I do not wish to use Flask-SQLAlchemy pattern (because of some points described in this article).

我是 Flask 的新手，所以如果问题过时、过多或错误，请多多包涵）我觉得应该有一些合理而清晰的解决方案，但无法触及它的方法。

Answer 1

我找到了解决办法。会 post 在这里以防有人遇到同样的问题。

首先，我这里有一个错误：

app.app_context:

我应该把上下文称为

app.app_context():

感谢。

其次， 我应该从 wsgi.py 中导入我的路由 app.app_context():

# defining app and db
abort = Abort(app, db)
app.config['database'] = db
app.config['abortion'] = abort
with app.app_context():
    from wallet import walletapp
    app.register_blueprint(walletapp.main)
app.run(debug=True)

而对于 last，我重写了 walletapp.py 如下：

app = current_app
    with app.app_context():
        db = current_app.config['database']
        abort = current_app.config['abortion']
        main = Blueprint('main', __name__)
# then goes @main.routes

在此模式中，代码运行良好。

从 Flask 蓝图访问数据库

Access database from Flask blueprint

python

sqlalchemy

blueprint

flask