On Sat, Apr 16, 2011 at 1:35 PM, Guevara <eguevara2...@gmail.com> wrote:
> Hello! > I have two class, Person and employee, i need make a composition for > this (Prefer composition over inheritance): > > class Person(models.Model): > name = models.CharField(max_length=50) > date_inclusion = models.DateField() > # others fields > > class Employee(models.Model): > person = models.OneToOneField(Person, primary_key=True) > address = models.OneToOneField(Address, primary_key=True) > > > The SQL generate is: > > > BEGIN; > CREATE TABLE "person_person" ( > "id" serial NOT NULL PRIMARY KEY, > "name" varchar(50) NOT NULL, > "date_inclusion" date NOT NULL, > ) > ; > CREATE TABLE "employee_employee" ( > "person_id" integer NOT NULL PRIMARY KEY, > "address_id" integer NOT NULL PRIMARY KEY, > ) > ; > > > This is correct? Should generate the id of the employee? > I don't think it's correct -- a database table shouldn't have two distinct primary keys. It's the "primary_key=True" part of your Employee model fields that is doing this, and is also stopping an "id" field from being automatically generated. If you write Employee like this: class Employee(models.Model): person = models.OneToOneField(Person) address = models.OneToOneField(Address) Then it will generate SQL like this: CREATE TABLE "employee_employee" ( "id" serial NOT NULL PRIMARY KEY, "person_id" integer NOT NULL, "address_id" integer NOT NULL ) ; which is probably closer to what you're expecting. -- Regards, Ian Clelland <clell...@gmail.com> -- You received this message because you are subscribed to the Google Groups "Django users" group. To post to this group, send email to django-users@googlegroups.com. To unsubscribe from this group, send email to django-users+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/django-users?hl=en.
