Flask中SQLAlchemy的代码：
errandorAuthentication = db.relationship(‘AuthenticationErrandor’, uselist=False, back_populates=”user”, foreign_keys=”AuthenticationErrandor.id”) class AuthenticationErrandor(db.Model): __tablename__ = ‘authenticationErrandors’ id = db.Column(db.String(64), primary_key=True, default = generateAuthErrandorId, nullable=False) userId = db.Column(db.String(64), db.ForeignKey(“users.id”)) user = db.relationship(“User”, back_populates=”errandorAuthentication”, foreign_keys=[userId]) |
运行出错：
Traceback (most recent call last): File “/root/Envs/RunningFast/lib/python2.7/site-packages/gevent/pywsgi.py”, line 884, in handle_one_response self.run_application() File “/root/Envs/RunningFast/lib/python2.7/site-packages/geventwebsocket/handler.py”, line 88, in run_application return super(WebSocketHandler, self).run_application() File “/root/Envs/RunningFast/lib/python2.7/site-packages/gevent/pywsgi.py”, line 870, in run_application self.result = self.application(self.environ, self.start_response) File “/root/Envs/RunningFast/lib/python2.7/site-packages/flask/app.py”, line 2000, in __call__ return self.wsgi_app(environ, start_response) File “/root/Envs/RunningFast/lib/python2.7/site-packages/flask_sockets.py”, line 48, in __call__ return self.wsgi_app(environ, start_response) File “/root/Envs/RunningFast/lib/python2.7/site-packages/flask/app.py”, line 1991, in wsgi_app response = self.make_response(self.handle_exception(e)) File “/root/Envs/RunningFast/lib/python2.7/site-packages/flask_restful/__init__.py”, line 271, in error_router return original_handler(e) File “/root/Envs/RunningFast/lib/python2.7/site-packages/flask/app.py”, line 1567, in handle_exception reraise(exc_type, exc_value, tb) File “/root/Envs/RunningFast/lib/python2.7/site-packages/flask_restful/__init__.py”, line 268, in error_router return self.handle_error(e) File “/root/Envs/RunningFast/lib/python2.7/site-packages/flask/app.py”, line 1988, in wsgi_app response = self.full_dispatch_request() File “/root/Envs/RunningFast/lib/python2.7/site-packages/flask/app.py”, line 1641, in full_dispatch_request rv = self.handle_user_exception(e) File “/root/Envs/RunningFast/lib/python2.7/site-packages/flask_restful/__init__.py”, line 271, in error_router return original_handler(e) File “/root/Envs/RunningFast/lib/python2.7/site-packages/flask/app.py”, line 1544, in handle_user_exception reraise(exc_type, exc_value, tb) File “/root/Envs/RunningFast/lib/python2.7/site-packages/flask_restful/__init__.py”, line 268, in error_router return self.handle_error(e) File “/root/Envs/RunningFast/lib/python2.7/site-packages/flask/app.py”, line 1639, in full_dispatch_request rv = self.dispatch_request() File “/root/Envs/RunningFast/lib/python2.7/site-packages/flask/app.py”, line 1625, in dispatch_request return self.view_functions[rule.endpoint](**req.view_args) File “/root/Envs/RunningFast/lib/python2.7/site-packages/flask_restful/__init__.py”, line 477, in wrapper resp = resource(*args, **kwargs) File “/root/Envs/RunningFast/lib/python2.7/site-packages/flask/views.py”, line 84, in view return self.dispatch_request(*args, **kwargs) File “/root/Envs/RunningFast/lib/python2.7/site-packages/flask_restful/__init__.py”, line 587, in dispatch_request resp = meth(*args, **kwargs) File “/root/RunningFast/staging/runningfast/resources/Accesstoken.py”, line 226, in post foundUser = User.query.filter_by(phone=phone).first() File “/root/Envs/RunningFast/lib/python2.7/site-packages/flask_sqlalchemy/__init__.py”, line 498, in __get__ mapper = orm.class_mapper(type) File “/root/Envs/RunningFast/lib/python2.7/site-packages/sqlalchemy/orm/base.py”, line 421, in class_mapper mapper = _inspect_mapped_class(class_, configure=configure) File “/root/Envs/RunningFast/lib/python2.7/site-packages/sqlalchemy/orm/base.py”, line 400, in _inspect_mapped_class mapper._configure_all() File “/root/Envs/RunningFast/lib/python2.7/site-packages/sqlalchemy/orm/mapper.py”, line 1222, in _configure_all configure_mappers() File “/root/Envs/RunningFast/lib/python2.7/site-packages/sqlalchemy/orm/mapper.py”, line 2840, in configure_mappers mapper._post_configure_properties() File “/root/Envs/RunningFast/lib/python2.7/site-packages/sqlalchemy/orm/mapper.py”, line 1765, in _post_configure_properties prop.init() File “/root/Envs/RunningFast/lib/python2.7/site-packages/sqlalchemy/orm/interfaces.py”, line 183, in init self.do_init() File “/root/Envs/RunningFast/lib/python2.7/site-packages/sqlalchemy/orm/relationships.py”, line 1653, in do_init self._setup_join_conditions() File “/root/Envs/RunningFast/lib/python2.7/site-packages/sqlalchemy/orm/relationships.py”, line 1728, in _setup_join_conditions can_be_synced_fn=self._columns_are_mapped File “/root/Envs/RunningFast/lib/python2.7/site-packages/sqlalchemy/orm/relationships.py”, line 1986, in __init__ self._determine_joins() File “/root/Envs/RunningFast/lib/python2.7/site-packages/sqlalchemy/orm/relationships.py”, line 2090, in _determine_joins “specify a ‘primaryjoin’ expression.” % self.prop) NoForeignKeysError: Could not determine join condition between parent/child tables on relationship User.errandorAuthentication – there are no foreign keys linking these tables. Ensure that referencing columns are associated with a ForeignKey or ForeignKeyConstraint, or specify a ‘primaryjoin’ expression. {‘CONTENT_LENGTH’: ’65’, ‘CONTENT_TYPE’: ‘application/json’, ‘GATEWAY_INTERFACE’: ‘CGI/1.1’, ‘HTTP_ACCEPT’: ‘*/*’, ‘HTTP_ACCEPT_ENCODING’: ‘gzip, deflate’, ‘HTTP_ACCEPT_LANGUAGE’: ‘zh-CN,zh;q=0.8,en;q=0.6’, ‘HTTP_CACHE_CONTROL’: ‘no-cache’, ‘HTTP_CONNECTION’: ‘keep-alive’, ‘HTTP_HOST’: ‘115.29.173.126:21085’, ‘HTTP_ORIGIN’: ‘chrome-extension://fhbjgbiflinjbdggehcddcbncdddomop’, ‘HTTP_POSTMAN_TOKEN’: ‘a01e4cd1-6f37-2e2a-68c6-117d087c4975’, ‘HTTP_USER_AGENT’: ‘Mozilla/5.0 (Macintosh; Intel Mac OS X 10_12_1) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/54.0.2840.98 Safari/537.36’, ‘PATH_INFO’: ‘/runningfast/api/v1.0/open/accesstoken’, ‘QUERY_STRING’: ”, ‘REMOTE_ADDR’: ‘58.209.164.112’, ‘REMOTE_PORT’: ‘64731’, ‘REQUEST_METHOD’: ‘POST’, ‘SCRIPT_NAME’: ”, ‘SERVER_NAME’: ‘AY140128113754462e2eZ’, ‘SERVER_PORT’: ‘21085’, ‘SERVER_PROTOCOL’: ‘HTTP/1.1’, ‘SERVER_SOFTWARE’: ‘gevent/1.1.2 gunicorn/19.6.0’, ‘werkzeug.request’: <Request ‘http://115.29.173.126:21085/runningfast/api/v1.0/open/accesstoken’ [POST]>, ‘wsgi.errors’: <gunicorn.http.wsgi.WSGIErrorsWrapper object at 0x7f01e62a5f50>, ‘wsgi.file_wrapper’: <class ‘gunicorn.http.wsgi.FileWrapper’>, ‘wsgi.input’: <gevent.pywsgi.Input object at 0x7f01e4abad50>, ‘wsgi.multiprocess’: False, ‘wsgi.multithread’: True, ‘wsgi.run_once’: False, ‘wsgi.url_scheme’: ‘http’, ‘wsgi.version’: (1, 0)} failed with NoForeignKeysError |
改为：
# errandorAuthentication = db.relationship(‘AuthenticationErrandor’, # uselist=False, # back_populates=”user”, # foreign_keys=”AuthenticationErrandor.id”) errandorAuthenticationId = db.Column(db.String(64), db.ForeignKey(“authenticationErrandors.id”)) errandorAuthentication = db.relationship(“AuthenticationErrandor”, back_populates=”user”, foreign_keys=[errandorAuthenticationId]) class AuthenticationErrandor(db.Model): __tablename__ = ‘authenticationErrandors’ id = db.Column(db.String(64), primary_key=True, default = generateAuthErrandorId, nullable=False) userId = db.Column(db.String(64), db.ForeignKey(“users.id”)) user = db.relationship(“User”, back_populates=”errandorAuthentication”, foreign_keys=[userId]) |
结果错误变成了：
Traceback (most recent call last): File “/root/Envs/RunningFast/lib/python2.7/site-packages/gevent/pywsgi.py”, line 884, in handle_one_response self.run_application() File “/root/Envs/RunningFast/lib/python2.7/site-packages/geventwebsocket/handler.py”, line 88, in run_application return super(WebSocketHandler, self).run_application() File “/root/Envs/RunningFast/lib/python2.7/site-packages/gevent/pywsgi.py”, line 870, in run_application self.result = self.application(self.environ, self.start_response) File “/root/Envs/RunningFast/lib/python2.7/site-packages/flask/app.py”, line 2000, in __call__ return self.wsgi_app(environ, start_response) File “/root/Envs/RunningFast/lib/python2.7/site-packages/flask_sockets.py”, line 48, in __call__ return self.wsgi_app(environ, start_response) File “/root/Envs/RunningFast/lib/python2.7/site-packages/flask/app.py”, line 1991, in wsgi_app response = self.make_response(self.handle_exception(e)) File “/root/Envs/RunningFast/lib/python2.7/site-packages/flask_restful/__init__.py”, line 271, in error_router return original_handler(e) File “/root/Envs/RunningFast/lib/python2.7/site-packages/flask/app.py”, line 1567, in handle_exception reraise(exc_type, exc_value, tb) File “/root/Envs/RunningFast/lib/python2.7/site-packages/flask_restful/__init__.py”, line 268, in error_router return self.handle_error(e) File “/root/Envs/RunningFast/lib/python2.7/site-packages/flask/app.py”, line 1988, in wsgi_app response = self.full_dispatch_request() File “/root/Envs/RunningFast/lib/python2.7/site-packages/flask/app.py”, line 1641, in full_dispatch_request rv = self.handle_user_exception(e) File “/root/Envs/RunningFast/lib/python2.7/site-packages/flask_restful/__init__.py”, line 271, in error_router return original_handler(e) File “/root/Envs/RunningFast/lib/python2.7/site-packages/flask/app.py”, line 1544, in handle_user_exception reraise(exc_type, exc_value, tb) File “/root/Envs/RunningFast/lib/python2.7/site-packages/flask_restful/__init__.py”, line 268, in error_router return self.handle_error(e) File “/root/Envs/RunningFast/lib/python2.7/site-packages/flask/app.py”, line 1639, in full_dispatch_request rv = self.dispatch_request() File “/root/Envs/RunningFast/lib/python2.7/site-packages/flask/app.py”, line 1625, in dispatch_request return self.view_functions[rule.endpoint](**req.view_args) File “/root/Envs/RunningFast/lib/python2.7/site-packages/flask_restful/__init__.py”, line 477, in wrapper resp = resource(*args, **kwargs) File “/root/Envs/RunningFast/lib/python2.7/site-packages/flask/views.py”, line 84, in view return self.dispatch_request(*args, **kwargs) File “/root/Envs/RunningFast/lib/python2.7/site-packages/flask_restful/__init__.py”, line 587, in dispatch_request resp = meth(*args, **kwargs) File “/root/RunningFast/staging/runningfast/resources/Accesstoken.py”, line 226, in post foundUser = User.query.filter_by(phone=phone).first() File “/root/Envs/RunningFast/lib/python2.7/site-packages/flask_sqlalchemy/__init__.py”, line 498, in __get__ mapper = orm.class_mapper(type) File “/root/Envs/RunningFast/lib/python2.7/site-packages/sqlalchemy/orm/base.py”, line 421, in class_mapper mapper = _inspect_mapped_class(class_, configure=configure) File “/root/Envs/RunningFast/lib/python2.7/site-packages/sqlalchemy/orm/base.py”, line 400, in _inspect_mapped_class mapper._configure_all() File “/root/Envs/RunningFast/lib/python2.7/site-packages/sqlalchemy/orm/mapper.py”, line 1222, in _configure_all configure_mappers() File “/root/Envs/RunningFast/lib/python2.7/site-packages/sqlalchemy/orm/mapper.py”, line 2837, in configure_mappers raise e InvalidRequestError: One or more mappers failed to initialize – can’t proceed with initialization of other mappers. Triggering mapper: ‘Mapper|AuthenticationErrandor|authenticationErrandors’. Original exception was: User.errandorAuthentication and back-reference AuthenticationErrandor.user are both of the same direction symbol(‘MANYTOONE’). Did you mean to set remote_side on the many-to-one side ? {‘CONTENT_LENGTH’: ’65’, ‘CONTENT_TYPE’: ‘application/json’, ‘GATEWAY_INTERFACE’: ‘CGI/1.1’, ‘HTTP_ACCEPT’: ‘*/*’, ‘HTTP_ACCEPT_ENCODING’: ‘gzip, deflate’, ‘HTTP_ACCEPT_LANGUAGE’: ‘zh-CN,zh;q=0.8,en;q=0.6’, ‘HTTP_CACHE_CONTROL’: ‘no-cache’, ‘HTTP_CONNECTION’: ‘keep-alive’, ‘HTTP_HOST’: ‘115.29.173.126:21085’, ‘HTTP_ORIGIN’: ‘chrome-extension://fhbjgbiflinjbdggehcddcbncdddomop’, ‘HTTP_POSTMAN_TOKEN’: ‘6d60edda-d662-31d3-9917-1cad7f6b918a’, ‘HTTP_USER_AGENT’: ‘Mozilla/5.0 (Macintosh; Intel Mac OS X 10_12_1) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/54.0.2840.98 Safari/537.36’, ‘PATH_INFO’: ‘/runningfast/api/v1.0/open/accesstoken’, ‘QUERY_STRING’: ”, ‘REMOTE_ADDR’: ‘58.209.164.112’, ‘REMOTE_PORT’: ‘63172’, ‘REQUEST_METHOD’: ‘POST’, ‘SCRIPT_NAME’: ”, ‘SERVER_NAME’: ‘AY140128113754462e2eZ’, ‘SERVER_PORT’: ‘21085’, ‘SERVER_PROTOCOL’: ‘HTTP/1.1’, ‘SERVER_SOFTWARE’: ‘gevent/1.1.2 gunicorn/19.6.0’, ‘werkzeug.request’: <Request ‘http://115.29.173.126:21085/runningfast/api/v1.0/open/accesstoken’ [POST]>, ‘wsgi.errors’: <gunicorn.http.wsgi.WSGIErrorsWrapper object at 0x7f19bac0af50>, ‘wsgi.file_wrapper’: <class ‘gunicorn.http.wsgi.FileWrapper’>, ‘wsgi.input’: <gevent.pywsgi.Input object at 0x7f19b89c87a0>, ‘wsgi.multiprocess’: False, ‘wsgi.multithread’: True, ‘wsgi.run_once’: False, ‘wsgi.url_scheme’: ‘http’, ‘wsgi.version’: (1, 0)} failed with InvalidRequestError |
再去改为：
class AuthenticationErrandor(db.Model): __tablename__ = ‘authenticationErrandors’ id = db.Column(db.String(64), primary_key=True, default = generateAuthErrandorId, nullable=False) userId = db.Column(db.String(64), db.ForeignKey(“users.id”)) # user = db.relationship(“User”, back_populates=”errandorAuthentication”, foreign_keys=[userId]) |
试试，结果：
InvalidRequestError: One or more mappers failed to initialize – can’t proceed with initialization of other mappers. Triggering mapper: ‘Mapper|User|users’. Original exception was: Mapper ‘Mapper|AuthenticationErrandor|authenticationErrandors’ has no property ‘user’ |
还是不行。
搜：
NoForeignKeysError: Could not determine join condition between parent/child tables on relationship
database – What is wrong with my relationships in SQL Alchemy? – Stack Overflow
InvalidRequestError: One or more mappers failed to initialize – can’t proceed with initialization of other mappers. Triggering mapper: ‘Mapper|User|users’. Original exception was: Mapper ‘Mapper|AuthenticationErrandor|authenticationErrandors’ has no property ‘user’ |
【总结】
最后用：
class User(db.Model): __tablename__ = ‘users’ id = db.Column(db.String(64), primary_key=True, default = generateUserId, nullable=False) errandorAuthenticationId = db.Column(db.String(64), db.ForeignKey(“authenticationErrandors.id”)) errandorAuthentication = db.relationship(‘AuthenticationErrandor’, uselist=False, # back_populates=”user”, foreign_keys=[errandorAuthenticationId]) class AuthenticationErrandor(db.Model): __tablename__ = ‘authenticationErrandors’ id = db.Column(db.String(64), primary_key=True, default = generateAuthErrandorId, nullable=False) # userId = db.Column(db.String(64), db.ForeignKey(“users.id”)) # user = db.relationship(“User”, back_populates=”errandorAuthentication”, foreign_keys=[userId]) |
就可以了。
转载请注明：在路上 » 【已解决】Flask的SQLAlchemy出错：NoForeignKeysError Could not determine join condition between parent child tables on relationship