我有一个SQLite数据库来管理用户登录以及现有的MySQL数据库。我将MySQL数据库添加到Flask-SQLAlchemy SQLALCHEMY_BINDS
配置中。当我尝试反映表时,我收到以下错误:
RuntimeError: application not registered on db instance and no application bound to current context
如何正确反映表格?
__init__.py
:
from flask import Flask
from flask.ext.sqlalchemy import SQLAlchemy
from config import config
db = SQLAlchemy()
def create_app(config_name):
app = Flask(__name__)
app.config.from_object(config[config_name])
config[config_name].init_app(app)
db.init_app(app)
from .main import main as main_blueprint
app.register_blueprint(main_blueprint)
return app
manage.py
:
from myapp import create_app
from flask.ext.migrate import Migrate, MigrateCommand
app = create_app(os.getenv('FLASK_CONFIG') or 'default')
manager = Manager(app)
migrate = Migrate(app, db)
manager.add_command('db', MigrateCommand)
if __name__ == '__main__':
manager.run()
models.py
:
from . import db, login_manager
db.Model.metadata.reflect(db.engine)
class Calls(db.Model):
__table__ = db.Model.metadata.tables['Calls2']
__bind_key__ = 'calls'
def __repr__(self):
return self.test1
Traceback (most recent call last):
File "./manage.py", line 6, in <module>
from app.models import User, Role, Permission
File "/home/ilias/Desktop/client-reporting/app/models.py", line 9, in <module>
db.Model.metadata.reflect(db.engine)
File "/home/ilias/Desktop/client-reporting/local/lib/python2.7/site-packages/flask_sqlalchemy/__init__.py", line 780, in engine
return self.get_engine(self.get_app())
File "/home/ilias/Desktop/client-reporting/local/lib/python2.7/site-packages/flask_sqlalchemy/__init__.py", line 809, in get_app
raise RuntimeError('application not registered on db '
RuntimeError: application not registered on db instance and no application bound to current context
答案 0 :(得分:4)
在使用应用程序初始化扩展程序之前,您无法对数据库执行操作,直到使用应用程序工厂函数时才会发生这种情况。在工厂内移动db.reflect
电话,并使用def create_app():
app = Flask(__name__)
...
db.init_app(app)
db.reflect(app=app)
# you could also push an app context instead of passing app
# with app.app_context():
# db.reflect()
...
return app
,它反映所有绑定,而不仅仅是主要绑定。
l
由于模型是作为视图的一部分导入的,这些视图仅在工厂内导入,因此元数据将在定义模型时包含反射表。