如何使用turbogears和sqlalchemy將數據保存在多對多的關係中

Question

嗨，我有一個用戶和group.and之間的多對多關係，我想添加一個用戶在我的數據庫中有許多組。這樣做，如果我的數據庫如下

user_group_table = Table('tg_user_group', metadata, 
    Column('user_id', Integer, ForeignKey('tg_user.user_id', 
     onupdate="CASCADE", ondelete="CASCADE")), 
    Column('group_id', Integer, ForeignKey('tg_group.group_id', 
     onupdate="CASCADE", ondelete="CASCADE")) 
) 

class Group(DeclarativeBase): 
    """ 
    Group definition for :mod:`repoze.what`.1 

    Only the ``group_name`` column is required by :mod:`repoze.what`. 

    """ 

    __tablename__ = 'tg_group' 

    #{ Columns 

    group_id = Column(Integer, autoincrement=True, primary_key=True) 

    group_name = Column(Unicode(16), unique=True, nullable=False) 

    display_name = Column(Unicode(255)) 

    created = Column(DateTime, default=datetime.now) 

    #{ Relations 

    users = relation('User', secondary=user_group_table, backref='groups') 

    #{ Special methods 

    def __repr__(self): 
     return '<Group: name=%s>' % self.group_name 

    def __unicode__(self): 
     return self.group_name 

    #} 
class User(DeclarativeBase): 
    """ 
    User definition. 

    This is the user definition used by :mod:`repoze.who`, which requires at 
    least the ``user_name`` column. 

    """ 
    __tablename__ = 'tg_user' 

    #{ Columns 

    user_id = Column(Integer, autoincrement=True, primary_key=True) 

    user_name = Column(Unicode(16), unique=True, nullable=False) 

    email_address = Column(Unicode(255), unique=True, nullable=False, 
          info={'rum': {'field':'Email'}}) 

    display_name = Column(Unicode(255)) 

    _password = Column('password', Unicode(80), 
         info={'rum': {'field':'Password'}}) 

    created = Column(DateTime, default=datetime.now) 

做不過這種方式給我一個錯誤

@expose() 
def user_save(self, **kw): 

    user = User() 
    user.user_name = kw['user_name'] 
    user.display_name = kw['display_name'] 
    user.email_address = kw['Email'] 
    user._password = kw['password'] 

    user.groups.extend(kw['groups']) 



    DBSession.add(user) 
    DBSession.flush() 
    flash("successfully saved...") 


    flash(user) 
    redirect("/user_new") 

請幫我解決this.thanks提前

Answer 1

我相信答案是呃你在問題中沒有發佈的消息。 user.groups是一個Group對象的列表，同時指定從表單獲取的字符串（？）列表。我也看到沒有明確的DBSession.commit()電話。你確定TurboGears會爲你做到嗎？