Question

我想连接两个型号。

模型＃1称为“组”。它通过starter_id，main_id，dessert_id连接到几个“团队”。我希望有一个名为“团队”的字段，其中包含所有已连接团队的列表。

class Group(db.Model):
    __tablename__ = 'groups'
    id = db.Column(db.Integer, primary_key=True)
    starter_id = db.Column(db.Integer, db.ForeignKey('teams.id'))
    main_id = db.Column(db.Integer, db.ForeignKey('teams.id'))
    dessert_id = db.Column(db.Integer, db.ForeignKey('teams.id'))

    #Relationships
    teams = db.relationship('Team', back_populates="group", foreign_keys= \
    [starter_1_id, starter_2_id, starter_3_id, main_1_id, main_2_id, main_3_id, \
    dessert_1_id, dessert_2_id, dessert_3_id])


class Team(db.Model):
    __tablename__ = 'teams'
    id = db.Column(db.Integer, primary_key=True)
    group_id = db.Column(db.Integer, db.ForeignKey('groups.id'))

    # Relationships
    group = db.relationship("Group", back_populates="teams", foreign_keys=[group_id])

我收到此错误：

sqlalchemy.exc.AmbiguousForeignKeysError: Could not determine join condition
between parent/child tables on relationship Group.teams - there are multiple
foreign key paths linking the tables.  Specify the 'foreign_keys' argument,
providing a list of those columns which should be counted as containing a
foreign key reference to the parent table.

我显然不知道如何修复该错误;）

Answer 1

一个团队属于一个团队＆＃34;关系（Team.group）及其逆，＆＃34;一个团队有很多团队＆＃34; （Group.teams）由外键Team.group_id给出，因此您需要写：

teams = db.relationship('Team', back_populates="group", foreign_keys=lambda: Team.group_id)

SQLAlchemy ManyToOne关系问题

1 个答案: