You have to create second form for PrinterAddress and handle both forms in you view: if all((profile_form.is_valid(), address_form.is_valid())): profile = profile_form.save() address = address_form.save(commit=False) address.printer_profile = profile address.save() Of course in the template you need to show both forms under one <form> tag 🙂 <form action=”” method=”post”> {% csrf_token %} {{ profile_form }} {{ address_form … Read more
From the logical standpoint, a 1:1 relationship should always be merged into a single table. On the other hand, there may be physical considerations for such “vertical partitioning” or “row splitting”, especially if you know you’ll access some columns more frequently or in different pattern than the others, for example: You might want to cluster … Read more
So you have a least two ways of checking that. First is to create try/catch block to get attribute, second is to use hasattr. class A(models.Model): def get_B(self): try: return self.b except: return None class B(models.Model): ref_a = models.OneToOneField(related_name=”ref_b”, null=True) Please try to avoid bare except: clauses. It can hide some problems. The second way … Read more
You told Hibernate to generate the EmployeeDetail ID from the ID of its employee property, but you never initialized this property. Add edetail.setEmployee(employee); to your code.
They look exactly the same on schema but there is difference on Hibernate Layer. If you try something like that: Address address = new Address(); Order order1 = new Order(); order1.setAddress(address); Order order2 = new Order(); order2.setAddress(address); save(); Everything will be OK. But, after save if you try get Order: @OneToOne case: org.hibernate.HibernateException: More than … Read more
Define a related_name to call the reverse accessor. a = models.OneToOneField(A, related_name=”foobar”) # … a.foobar
Since Primary Keys are UNIQUE by default, this makes this relation One to One. No, that makes the relation “one to zero or one”. Is that what you actually need? If yes, then then your “second solution” is better: it’s simpler, takes less storage1 (and therefore makes cache “larger”) hes less indexes to maintain2, which … Read more
It’s perfectly possible to use an inline for a OneToOne relationship. However, the actual field defining the relationship has to be on the inline model, not the parent one – in just the same way as for a ForeignKey. Switch it over and it will work. Edit after comment: you say the parent model is … Read more
I’m pretty sure it is technically impossible in SQL Server to have a True 1 to 1 relationship, as that would mean you would have to insert both records at the same time (otherwise you’d get a constraint error on insert), in both tables, with both tables having a foreign key relationship to each other. … Read more
To map one-to-one association using shared primary keys use @PrimaryKeyJoinColumn and @MapsId annotation. Relevant sections of the Hibernate Reference Documentation: PrimaryKeyJoinColumn The PrimaryKeyJoinColumn annotation does say that the primary key of the entity is used as the foreign key value to the associated entity. MapsId The MapsId annotation ask Hibernate to copy the identifier from … Read more