我有好几个班都有同样的关系。例如:
class Foo(db.Model):
__tablename__ = 'foo'
foonr = Column('foonr', Integer, primary_key=True)
bar= Column('bar_code',String, ForeignKey('bar.bar_code'))
bar_rel = relationship('Foo', back_populates='foo_rel')
class Bar(db.Model):
__tablename__ = 'bar'
code = Column('bar_code', String, primary_key=True)
foo_rel = relationship('Foo', uselist=False, back_populates=' bar_rel')
这几乎是来自:http://docs.sqlalchemy.org/en/latest/orm/basic_relationships.html的复制粘贴。但是,在这个例子中,当我试图查询一个无关的类(不是Foo或Bar)时,我得到了以下错误:
sqlalchemy.exc.NoForeignKeysError: Could not determine join condition between parent/child tables on relationship ... - there are no foreign keys linking these tables. Ensure that referencing columns are associated with a ForeignKey or ForeignKeyConstraint, or specify a 'primaryjoin' expression.
有人能解释一下这种行为吗?帮我解决这个问题?在
谢谢。在
类
Foo
中的relationship
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