Book Image

Mastering Entity Framework

By : Rahul Rajat Singh
Book Image

Mastering Entity Framework

By: Rahul Rajat Singh

Overview of this book

<p>Data access is an integral part of any software application. Entity Framework provides a model-based system that makes data access effortless for developers by freeing you from writing similar data access code for all of your domain models.</p> <p>Mastering Entity Framework provides you with a range of options when developing a data-oriented application. You’ll get started by managing the database relationships as Entity relationships and perform domain modeling using Entity Framework. You will then explore how you can reuse data access layer code such as stored procedures and table-valued functions, and perform various typical activities such as validations and error handling. You’ll learn how to retrieve data by querying the Entity Data Model and understand how to use LINQ to Entities and Entity SQL to query the Entity Data Model.</p>
Table of Contents (19 chapters)
Mastering Entity Framework
Credits
About the Author
About the Reviewers
www.PacktPub.com
Preface
Index

Modeling a one-to-one relationship using Entity Framework


Now, let's look at the models that have one-to-one relationships. The Employees table and Passports table has a one-to-one relationship. If we look at the Employee and Passport relationship, we can see that the Entity Framework Entity Data Model generator was able to figure out the one-to-one relationship between these tables and was able to create the same relationship in the conceptual Entity Data Model as well.

A one-to-one relationship between entities

Also, one-to-one relationships in the Entity Data Model are represented by 1 with the Employee entity, because this is the main entity in the relation. The Passport entity shows 0..1, which means that there could be either 0 or 1 entries in the Passport table for each employee.

Entity Framework also created Navigation Properties in the entities. Navigation properties are properties that link the entities to related entities. Using navigation properties, we can access the entities related...