[Error] sqlalchemy.exc.NoForeignKeysError

오류

sqlalchemy.exc.NoForeignKeysError

: Could not determine join condition between parent/child tables on relationship FaceRequestsDB.facial_expression - there are no foreign keys linking these tables. Ensure that referencing columns are associated with a ForeignKey or ForeignKeyConstraint, or specify a 'primaryjoin' expression.

(...중간 생략)
      File "/경로/경로/lib/python3.10/site-packages/sqlalchemy/util/compat.py", line 211, in raise_
        raise exception
    sqlalchemy.exc.NoForeignKeysError: Could not determine join condition between parent/child tables on relationship FaceRequestsDB.facial_expression - there are no foreign keys linking these tables.  Ensure that referencing columns are associated with a ForeignKey or ForeignKeyConstraint, or specify a 'primaryjoin' expression.

원인

facial = relationship 으로 FacialDB로 연결해놨는데 컬럼에는 어디에 사용한다는 foreignkey를 명시한게 없어서 오류가 발생

class FaceRequestsDB(Base):
    __tablename__ = 'face_requests'

    id = Column(Integer, primary_key=True, index=True)
    user_id = Column(ForeignKey('users.id'), index=True)
    (...중간생략)
    format = Column(String(45))

    user = relationship('UsersDB')
    facial = relationship('FacialDB')

해결

class FaceRequestsDB(Base):
    __tablename__ = 'face_requests'

    id = Column(Integer, primary_key=True, index=True)
    user_id = Column(ForeignKey('users.id'), index=True)
    (...중간생략)
    format = Column(String(45))
    facial_id = Column(ForeignKey('facial.id'), index=True)  # 수정 부분

    user = relationship('UsersDB')
    facial = relationship('FacialDB')