What are different types of inheritance in Entity Framework?

What are different types of inheritance in Entity Framework?

Inheritance in the Entity Framework is similar to inheritance for classes in C#….Understanding Inheritance in Entity Framework

• Table-per-Hierarchy (TPH)
• Table-per-Concrete-Type (TPC)
• Table-per-Type (TPT)

How is inheritance implemented in Entity Framework?

In this tutorial, you:

1. Learn to map inheritance to database.
2. Create the Person class.
3. Update Instructor and Student.
4. Add Person to the Model.
5. Create and Update Migrations.
6. Test the implementation.
7. Deploy to Azure.

What is table-per-type?

Table-per-type inheritance uses a separate table in the database to maintain data for non-inherited properties and key properties for each type in the inheritance hierarchy. The EF Designer uses the TPT strategy by default and so any inheritance in the model will be mapped to separate tables.

What do you mean by table Per hierarchy?

An entire class hierarchy can be mapped to a single table. This table includes columns for all properties of all classes in the hierarchy. The concrete subclass represented by a particular row is identified by the value of a type discriminator column.

What is inheritance in MVC?

Acquiring (taking) the properties of one class into another class is called inheritance. Inheritance provides reusability by allowing us to extend an existing class. The reason behind OOP programming is to promote the reusability of code and to reduce complexity in code and it is possible by using inheritance.

What is Entitystate?

EF API maintains the state of each entity during its lifetime. Each entity has a state based on the operation performed on it via the context class. The entity state represented by an enum System.

What is TPH inheritance?

TPH inheritance uses one database table to maintain data for all of the entity types in an inheritance hierarchy. We’ll create a conceptual model from the database (Database First) and then alter the model to implement the TPH inheritance using the EF Designer.

Which annotation is used to identify the class in inheritance?

JPA Inheritence Annotations @MappedSuperclass – This annotation is applied to the classes that are inherited by their subclasses. The mapped superclass doesn’t contain any separate table.

How does table per type inheritance in TPT work?

Table-per-type inheritance uses a separate table in the database to maintain data for non-inherited properties and key properties for each type in the inheritance hierarchy. In this walkthrough we will map the Course (base type), OnlineCourse (derives from Course), and OnsiteCourse (derives from Course) entities to tables with the same names.

How to implement TPT inheritance in Entity Framework designer?

This step-by-step walkthrough shows how to implement table-per-type (TPT) inheritance in your model using the Entity Framework Designer (EF Designer). Table-per-type inheritance uses a separate table in the database to maintain data for non-inherited properties and key properties for each type in the inheritance hierarchy.

How to create a TPT mapping for a table?

We can create a TPT mapping simply by placing Table attribute on the subclasses to specify the mapped table name. Here is the very simple model which contains one abstract class Person and two non-abstract classes Student and Teacher. Student and Teacher classes inherit the Person class.

Which is an example of a Polymorphic association in TPT?

In other words, as you can see above, a polymorphic association is an association that may refer instances of a subclass of the class that was explicitly specified as the type of the navigation property (e.g. User.BillingInfo). Another important advantage of TPT is the ability to handle polymorphic associations.