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You're reading from Mastering Entity Framework Core 2.0 Dive into entities, relationships, querying, performance optimization, and more, to learn efficient data-driven development

Product type Paperback

Published in Dec 2017

Publisher Packt

ISBN-13 9781788294133

Length 386 pages

Edition 1st Edition

Languages

Tools

.NET Core

Concepts

Application Development

Author (1):

Prabhakaran Anbazhagan

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Table of Contents (13) Chapters

Preface

1. Kickstart - Introduction to Entity Framework Core

2. The Other Way Around – Database First Approach FREE CHAPTER

3. Relationships – Terminology and Conventions

4. Building Relationships – Understanding Mapping

5. Know the Validation – Explore Inbuilt Validations

6. Save Yourself – Hack Proof Your Entities

7. Going Raw – Leveraging SQL Queries in LINQ

8. Query Is All We Need – Query Object Pattern

9. Fail Safe Mechanism – Transactions

10. Make It Real – Handling Concurrencies

11. Performance – It's All About Execution Time

12. Isolation – Building a Multi-Tenant Database

Conventions in a relationship

By now, we should be able to say that relationships are identified by Entity Framework while it is analyzing our data model. So, from the preceding section, it is evident that we should have a navigation property in both the entities for a relationship.

Note

While analyzing the relationship, Entity Framework can only identify a primary key on its own. But, if we use an alternate key for a relationship, then explicitly we should mark it as the principal key using the Fluent API. In our blogging system, the implementation in OnModelCreating would be as follows:modelBuilder.Entity<Post>().HasOne(p => p.Blog).WithMany(b => b.Posts).HasForeignKey(p => p.BlogUrl).HasPrincipalKey(b => b.Url);

It's also evident that, for any relationship, we need a property that should be against a data model and not a scalar datatype (it would be ignored by EF for relationships).