python - SqlAlchemy 加入没有外键的表

Question

我在 SqlAlchemy 中有两个表

class T1(Record, SqlBase):
    __tablename__ = 'table1'
    __table_args__ = (PrimaryKeyConstraint('column'), {'autoload': True},)

class T2(Record, SqlBase):
    __tablename__ = 'table2'
    __table_args__ = (PrimaryKeyConstraint('column'), {'autoload': True},)

我想在一些公共(public)列上连接两个表

session.query(T1).join(session.query(T2), T1.column == T2.column)

但是我遇到了一个错误

InvalidRequestError: Could not find a FROM clause to join from.  Tried joining to 
... but got: Can't find any foreign key relationships 
between 'T1' and 'FromGrouping object'. Perhaps you
 meant to convert the right side to a subquery using alias()?

如何解决这个问题？两张表都没有外键

Answer 1

有用 Doc

如果两个类都有关系，你可以使用 join，或者你可以像这样写没有 join 的查询

session.query(T1).filter(T1.column == T2.column)