python - 由于一个或多个映射器初始化失败，无法在 SQLAlchemy 中创建记录

Question

我有一个模型文件(简化版)

repo 只有一个用户，一个用户可以有多个 repo 。

class Repo(Base):
    __tablename__ = "repos"

    id = db.Column(db.Integer, primary_key=True)
    name = db.Column(db.String(512), unique=True)
    user_id = Column(Integer, ForeignKey('users.id'))
    user = db.relationship("User", back_populates="users")

class User(Base):
    __tablename__ = 'users'

    id = db.Column(db.Integer, primary_key=True)
    name = db.Column(db.String(200), unique=True)
    repos = db.relationship("User", back_populates="repos")

当我尝试插入记录时出现错误:

One or more mappers failed to initialize - can't proceed with initialization of other mappers. Original exception was: Mapper 'Mapper|User|users' has no property 'users'

如何修复我的模型？

Answer 1

back_populates 对于 user 关系应该是 repos，对于 repos 关系应该是 user

class Repo(Base):
    __tablename__ = "repos"

    id = db.Column(db.Integer, primary_key=True)
    name = db.Column(db.String(512), unique=True)
    user_id = Column(Integer, ForeignKey('users.id'))
    user = db.relationship("User", back_populates="repos")

class User(Base):
    __tablename__ = 'users'

    id = db.Column(db.Integer, primary_key=True)
    name = db.Column(db.String(200), unique=True)
    repos = db.relationship("Repo", back_populates="user")