Table of Contents
Do foreign keys get automatically update?
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 is foreign key used in Entity Framework?
Entity Framework ForeignKey. ForeignKey. code-first. fluent-api. data-annotations. The ForeignKey attribute is used to specify which property is the foreign key in a relationship. It is used to express the relationship between two tables.
Where do I put the foreignkey attribute in EF 7?
The [ForeignKey] attribute can be applied to the navigation property in the principal entity and the related foreign key property name can be specified in the dependent entity, as shown below. In the above example, the [ForeignKey] attribute is applied on the Students navigation property in the principal entity Standard.
How does relationship fix up work in Entity Framework?
When you change the relationship of the objects attached to the context by using one of the methods described above, Entity Framework needs to keep foreign keys, references, and collections in sync. Entity Framework automatically manages this synchronization (also known as relationship fix-up) for the POCO entities with proxies.
Why does Entity Framework reinsert existing data points?
The Screencast that’s sent to the repository method is now just the single entity, not a graph. Entity Framework can use the foreign key property to directly set the table’s TopicId. Then it’s simple (and faster) for EF to create an insert method for the Screencast entity including the TopicId (in my case, the value 2):
How to create new foreign key in Entity Framework?
That might be because entity framework is trying to create new foreign key based on navigation property Country in Person entity. I think you should annotate Country_Id property with ForeignKey attribute as below.
When to use the foreignkey attribute in EF 6?
The ForeignKey attribute is used to configure a foreign key in the relationship between two entities in EF 6 and EF Core. It overrides the default conventions. As per the default convention, EF makes a property as foreign key property when its name matches with the primary key property of a related entity.
When does an EF property become a foreign key?
As per the default convention, EF makes a property as foreign key property when its name matches with the primary key property of a related entity. ForeignKey Signature:
When you change the relationship of the objects attached to the context by using one of the methods described above, Entity Framework needs to keep foreign keys, references, and collections in sync. Entity Framework automatically manages this synchronization (also known as relationship fix-up) for the POCO entities with proxies.