Hello. Please take a look at official examples:
http://docs.sqlalchemy.org/en/rel_1_0/orm/backref.html?highlight=back_populates The first two examples use your classes (User and Address). Note the use of backref kw arg in the relationship definition (first example) and back_populates kw arg in the second example. I personally prefer back_populates because each ORM definition is then complete on its own (i.e. both User and Address will each define the appropriate relationship connected to the other with back_populates kw). HTH, Ladislav Lenart On 11.8.2015 09:59, Sean Lin wrote: > Dear all, > > I have a question about how to automatic set the foreignkey column ? > > > we have two class User and Address > > | > > classUser(Base): > __tablename__ ='user' > id =Column(Integer,primary_key=True) > name =Column(String) > addresses =relationship("Address") > def__init__(self,id,name): > self.id =id > self.name =name > > classAddress(Base): > __tablename__ ='address' > id =Column(Integer,primary_key=True) > user_id =Column(Integer,ForeignKey('user.id')) > def__init__(self,id,user_id): > self.id =id > self.user_id =user_id > > | > > if we create a user then add a address > > | > > User1=User(1,"Tom") > Address1=Address('1',None) > User1.addresses(Address1) > printUser1.Address[0].user_id > > | > > after that we will get a None result ... > > How to automatic assign user_id when we add address to a user? -- You received this message because you are subscribed to the Google Groups "sqlalchemy" group. To unsubscribe from this group and stop receiving emails from it, send an email to sqlalchemy+unsubscr...@googlegroups.com. To post to this group, send email to sqlalchemy@googlegroups.com. Visit this group at http://groups.google.com/group/sqlalchemy. For more options, visit https://groups.google.com/d/optout.
