Book Image

Entity Framework Core Cookbook - Second Edition

By : Ricardo Peres
Book Image

Entity Framework Core Cookbook - Second Edition

By: Ricardo Peres

Overview of this book

Entity Framework is a highly recommended Object Relation Mapping tool used to build complex systems. In order to survive in this growing market, the knowledge of a framework that helps provide easy access to databases, that is, Entity Framework has become a necessity. This book will provide .NET developers with this knowledge and guide them through working efficiently with data using Entity Framework Core. You will start off by learning how to efficiently use Entity Framework in practical situations. You will gain a deep understanding of mapping properties and find out how to handle validation in Entity Framework. The book will then explain how to work with transactions and stored procedures along with improving Entity Framework using query libraries. Moving on, you will learn to improve complex query scenarios and implement transaction and concurrency control. You will then be taught to improve and develop Entity Framework in complex business scenarios. With the concluding chapter on performance and scalability, this book will get you ready to use Entity Framework proficiently.
Table of Contents (15 chapters)
Entity Framework Core Cookbook - Second Edition
Credits
About the Author
About the Reviewer
www.PacktPub.com
Preface
Index

Retrieving entity metadata


When you create an Entity Framework context, you map a domain model to a data store. Specifically, in the case of relational databases, you assign the following:

  • Classes to tables

  • Properties to columns

  • References to foreign keys

Of course, in normal usage, you normally don't need to worry about these mappings; you just query the POCO domain model and that's it. But if you need to write SQL for more advanced queries, you are left with two options:

  • You know exactly the database names of all the tables and columns (keep in mind that the class Person can be mapped to, say, PERSON, PEOPLE, PERSON_DETAIL, PERSON_DETAILS, and so on)

  • You obtain this information dynamically at runtime

If you want to be safe, you will stick to the second option and obtain all the information you need whenever you need it; this way, you know you're not wrong. That's what this chapter is about, after all!

Getting ready

We will be using the NuGet Package Manager to install the Entity Framework Core...