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Do you need to configure one to many relationship in Entity Framework?
Generally, you don’t need to configure the one-to-many relationship in entity framework because one-to-many relationship conventions cover all combinations. However, you may configure relationships using Fluent API at one place to make it more maintainable. Consider the following Student and Grade entity classes.
How are many to many relationships managed in EF 6?
Student can join multiple courses and multiple students can join one Course . Visit the Entity Relationship chapter to understand how EF manages one-to-one, one-to-many and many-to-many relationships between entities. EF 6 includes default conventions for many-to-many relationships.
How to use EF code first approach in Entity Framework?
As you know, the EF Code First approach follows convention over configuration, so in the constructor, we just pass the connection string name same as an App.Config file and it connects to that server. In the OnModelCreating () method, we used a reflection to map an entity to its configuration class in this specific project.
How are navigation and relationship properties used in EF?
Relationships in EF. Every object can have a navigation property for every relationship in which it participates. Navigation properties allow you to navigate and manage relationships in both directions, returning either a reference object (if the multiplicity is either one or zero-or-one) or a collection (if the multiplicity is many).
How to establish one to many relationship in EF6?
Let’s say we have Author and Book entities. In EF6, most of the times you don’t need to configure the one-to-many relationship because one-to-many relationship conventions cover all combinations. You can establish a one-to-many relationship by using any of the following code first conventions.
In Entity Framework you commonly use navigation properties to load entities that are related to the returned entity by the defined association. For more information, see Loading Related Objects. // Get the course where currently DepartmentID = 2.
How to create a student entity in Entity Framework 6?
So, modelBuilder.Entity () starts with the Student entity. Then, .HasRequired (s => s.CurrentGrade) specifies that the Student entity has required the CurrentGrade property. This will create a NotNull foreign key column in the DB.