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Can a foreign key reference a property other than the primary key?
If you want the foreign key to reference a property other than the primary key, you can use the Fluent API to configure the principal key property for the relationship. The property that you configure as the principal key will automatically be set up as an alternate key.
When do you include a foreign key in a relationship?
Note, that when working with 1-to-1 or 1-to-0..1 relationships, there is no separate foreign key column, the primary key property acts as the foreign key and is always included in the model. When foreign key columns are not included in the model, the association information is managed as an independent object.
How to reverse lookup foreign keys in Django?
My current view looks like: You can use events = venue.event_set to go the other way. Note that venue.event_set is a manager object, like Event.objects, so you can call .all, .filter, .exclude and similar on it to get a queryset. Add all to retrieve the elements from the manager. Go the other way round.
Where are the foreign key properties located in EF Core?
The foreign key properties are located on the dependent entity type, so if they are configured as required it means that every dependent entity is required to have a corresponding principal entity. Calling IsRequired (false) also makes the foreign key property optional unless it’s configured otherwise.
Is the foreign key updated automatically with cascaded way?
and get that fileds are updated and deleted with cascaded way. No the foreign key is not updated automatically. You need to update the foreign key in the tables in which it is referenced by yourself else it would result in referential integrity exception. For updating the foreign key automatically you may use TRIGGERS.
How to configure composite foreign keys in Microsoft Docs?
For composite foreign keys, becomes an underscore separated list of foreign key property names. You can also configure the constraint name as follows: You don’t necessarily need to provide a navigation property. You can simply provide a foreign key on one side of the relationship.
Do you need a foreign key property in dependent entity class?
While it is recommended to have a foreign key property defined in the dependent entity class, it is not required.