我的感情(…)有问题,我不明白为什么。
错误:
"InvalidRequestError:当初始化mapper mapper |User|users时,表达式'BannedUser'未能找到名称("name 'BannedUser' is not defined")。如果这是一个类名,请考虑在定义了两个依赖类之后将这个relationship()添加到类中。"
这是代码:
用户模型from sqlalchemy.ext.declarative import declarative_base
from sqlalchemy import Column, Integer, String
from sqlalchemy.orm import relationship
from .base import Base as BaseModel
class User(BaseModel, declarative_base()):
__tablename__ = 'users'
id = Column(Integer, primary_key=True)
username = Column(String(16))
password = Column(String(16))
nickname = Column(String(16))
secret_question = Column(String(50))
secret_answer = Column(String(50))
role = Column(Integer)
is_banned = relationship("BannedUser", uselist=False, back_populates='users')
禁用用户模型:
from sqlalchemy.ext.declarative import declarative_base
from sqlalchemy import Column, Integer, String, DateTime, ForeignKey
from sqlalchemy.orm import relationship
from .base import Base as BaseModel
class BannedUser(BaseModel, declarative_base()):
__tablename__ = 'banned_users'
id = Column(Integer, primary_key=True)
user_id = Column(Integer, ForeignKey('users.id'))
user = relationship('User', back_populates='banned_users')
reason = Column(String)
time_end = Column(DateTime)
我尝试直接类而不是类字符串,但这也不起作用。
我试过"用户"。Id '而不是'users '。,但同样的事情发生了。
我不知道该怎么办。
提前感谢您的帮助
在back_populates
(doc)上,您需要指定与关系的另一端相关的属性,而您指定了表名…同一实体的…
我建议使用back_ref
(doc),它负责另一端相关的属性(因此您不需要在BannedUser
上指定user
属性,或者相反),例如:
...
class User(BaseModel, declarative_base()):
__tablename__ = 'users'
...
is_banned = relationship("BannedUser", uselist=False, back_ref='user')
...
但是如果你仍然想用back_populates
来做,你应该这样做:
...
class User(BaseModel, declarative_base()):
__tablename__ = 'users'
...
is_banned = relationship("BannedUser", uselist=False, back_populates='user')
...
class BannedUser(BaseModel, declarative_base()):
__tablename__ = 'banned_users'
...
user = relationship('User', back_populates='is_banned')
...