Book Image

NHibernate 4.x Cookbook - Second Edition

By : Gunnar Liljas, Alexander Zaytsev, Jason Dentler
Book Image

NHibernate 4.x Cookbook - Second Edition

By: Gunnar Liljas, Alexander Zaytsev, Jason Dentler

Overview of this book

NHibernate is a mature, flexible, scalable, and feature-complete open source project for data access. Although it sounds like an easy task to build and maintain database applications, it can be challenging to get beyond the basics and develop applications that meet your needs perfectly. NHibernate allows you to use plain SQL and stored procedures less and keep focus on your application logic instead. Learning the best practices for a NHibernate-based application will help you avoid problems and ensure that your project is a success. The book will take you from the absolute basics of NHibernate through to its most advanced features, showing you how to take full advantage of each concept to quickly create amazing database applications. You will learn several techniques for each of the four core NHibernate tasks—configuration, mapping, session and transaction management, and querying—and which techniques fit best with various types of applications. In short, you will be able to build an application using NHibernate by the end of the book. You will also learn how to best implement enterprise application architecture patterns using NHibernate, leading to clean, easy-to-understand code and increased productivity. In addition to new features, you will learn creative ways to extend the NHibernate core, as well as gaining techniques to work with the NHibernate search, shards, spatial, envers, and validation projects.
Table of Contents (17 chapters)
NHibernate 4.x Cookbook Second Edition
Credits
About the Authors
About the Reviewer
www.PacktPub.com
Customer Feedback
Preface
Index

Setting up a base entity class


In this recipe, we'll show how to set up a base class for your entities. The purpose of this class is to provide base implementations of potentially tricky Equals and GetHashCode methods.

How to do it…

  1. We create a base class, where the type of Id is specified using a generic argument, as shown:

    public abstract class Entity<TId>
    {
    
      public virtual TId Id { get; protected set; }
    
      public override bool Equals(object obj)
      {
        return Equals(obj as Entity<TId>);
      }
    
      private static bool IsTransient(Entity<TId> obj)
      {
        return obj != null &&
               Equals(obj.Id, default(TId));
      }
    
      private Type GetUnproxiedType()
      {
        return GetType();
      }
    
      public virtual bool Equals(Entity<TId> other)
      {
        if (other == null)
          return false;
    
        if (ReferenceEquals(this, other))
          return true;
    
        if (!IsTransient(this) &&
            !IsTransient(other) &&
            Equals(Id, other.Id))
        {
          var otherType...