many-to-many

I need to create my own intermediate model. class class1(models.Model) class class2(models.Model): field1 = models.ManyToManyField(class1, through="class3") class class3(models.Model): field1 = models.ForeignKey(class1) field2 = models.ForeignKey(class2) field3 = models.IntegerField() class Meta: auto_created = True I use "auto_created=True" because in the following code, I had the error : AttributeError: Cannot use add() on a ManyToManyField which specifies an intermediary model. for m2m_field in self._meta.many_to_many: for m2m_link in getattr(self, m2m_field.get_attname()).all(): getattr(to

Is there a way to query for subset or superset containment with many-to-many fields? Suppose each Person has a list of birds they want to see, and each Aviary houses a list of birds. How can I make a query to find, for a given Person instance, which Aviaries have every bird on the person's list? And similarly, for a given Person instance, how do I find which Aviaries have only birds on the person's list (but not necessarily all of them). Here are my Django 1.5 models: class Bird(models.Model): name = models.CharField(max_length=255, unique=True) class Aviary(models.Model): name = models

What is the method to save and update Many to Many relationship in Yii framework? There is a better implementation as behavior. http://www.yiiframework.com/forum/index.php?/topic/6905-please-test-my-ar-enhancement-automatically-sync-many-many-table-when-calling-save/ Unless you create a model for the table between the two main tables, your only option is to use DAO (Database Access Object) and specify SQLs with it. Have a look at how blog demo accomplishes this task. user318750 use MANY_MANY relationship type to setup many to many connection between Models (An associative table is needed to

I'm trying to make a self-referential many-to-many relationship (it means that Line can have many parent lines and many child lines) in sqlalchemy like this: Base = declarative_base() class Association(Base): __tablename__ = 'association' prev_id = Column(Integer, ForeignKey('line.id'), primary_key=True) next_id = Column(Integer, ForeignKey('line.id'), primary_key=True) class Line(Base): __tablename__ = 'line' id = Column(Integer, primary_key = True) text = Column(Text) condition = Column(Text) action = Column(Text) next_lines = relationship(Association, backref="prev_lines") class Root(Base):

Entities: Team <-> TeamEmployee <-> Employee Requirements: A Team and an Employee can exist without its counterpart. In the Team-TeamEmployee relation the Team is responsible (parent) [using later a TeamRepository]. In the Employee-TeamEmployee relation the Employee is responsible (parent) [using later an EmployeeRepository]. Duplicates are not allowed. Deleting a Team deletes all Employees in the Team, if the Employee is not in another Team. Deleting an Employee deletes only a Team, if the Team does not contain no more Employees. Mapping: public class TeamMap : ClassMap<Team> { public TeamMap