NHibernate 4.x Cookbook - Second Edition

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.

NHibernate 4.x Cookbook Second Edition

NHibernate 4.x Cookbook Second Edition

Credits

About the Authors

About the Authors

About the Reviewer

About the Reviewer

www.PacktPub.com

www.PacktPub.com

Customer Feedback

Customer Feedback

Preface

Free Chapter

The Configuration and Schema

The Configuration and Schema

Installing NHibernate

Configuring NHibernate with hibernate.cfg.xml

Configuring NHibernate with App.config or Web.config

Configuring NHibernate with code

Configuring NHibernate with Fluent NHibernate

Configuring NHibernate logging

Generating the database

Scripting the database

Updating the database

Using NHibernate schema tool

Models and Mappings

Models and Mappings

Mapping a class with XML

Creating class hierarchy mappings

Creating class components

Mapping a one-to-many relationship

Mapping a many-to-many relationship

Mapping collections of elements and components

Setting up a base entity class

Handling versioning and concurrency

Mapping by code

Mapping by convention

Creating mappings fluently

Bidirectional one-to-many class relationships

Mapping enumerations

Immutable entities

Mapping relations to non-primary keys

Using lazy properties

Using calculated properties

Using serializable values

Dynamic components

Mapping <subselect>

Sessions and Transactions

Sessions and Transactions

Setting up session-per-web request

Setting up session-per-presenter

Creating a session ASP.NET MVC action filter

Creating a transaction ASP.NET MVC action filter

Save entities to the database

Using session.Merge

Using session.Refresh

Handle concurrency using session.Lock

There's more…

Using dictionaries as entities

Using NHibernate with transaction scope

Queries

Query entities by ID

Using LINQ to NHibernate

Using CriteriaQueries

Using QueryOver

Using QueryOver projections and aggregates

Using the Hibernate Query Language

Using native SQL

Eager loading with LINQ

Eager loading with Criteria

Eager loading with QueryOver

Eager loading with HQL

Eager loading with SQL

Using named queries

Using detached queries

Using HQL for bulk data changes

Filtering collections

Using result transformers

Extra lazy collections

Improving Performance

Improving Performance

Reducing application startup time

Using MultiCriteria

Using MultiQuery

Eager loading child collections

Using stateless sessions

Using read-only entities

Use the second-level cache

Configuring the second-level cache with code

Sharding databases for performance

Testing

Using NHibernate Profiler

Profiling NHibernate with Glimpse

Fast testing with the SQLite in-memory database

Preloading data with SQLite

Using Fluent NHibernate persistence testing

Using the Ghostbusters test

Data Access Layer

Data Access Layer

Transaction auto-wrapping for the data access layer

Setting up an NHibernate repository

Using named queries in the data access layer

Using ICriteria in the data access layer

Using paged queries in the data access layer

Using LINQ specifications in the data access layer

Extending NHibernate

Extending NHibernate

Creating an encrypted string type

Creating a money type

Using well-known instance types

Using dependency injection with entities

Creating an audit-event listener

Creation and change stamping of entities

Generating trigger-based auditing

Implementing a soft-delete pattern

Setting Microsoft SQL's Context_Info

Using dynamic connection strings

Using custom dialect functions

Using custom functions in LINQ

Extending the LINQ provider

NHibernate Contribution Projects

NHibernate Contribution Projects

Property validation with attributes

Creating validator classes

Setting up full-text searches

Auditing data with Envers

Using NHibernate Spatial

Index

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Using custom dialect functions

In this recipe, we will show how you can add mappings for database functions, which are not available by default.

How to do it…

Create a new class library project named CustomDialectExample.
Install the NHibernate and log4net packages using the NuGet Package Manager Console by executing the following command:
```
Install-Package NHibernate
Install-Package log4net
```

Create a new class named CustomMsSql2012Dialect using the following code:

public class CustomMsSq2012Dialect:
  MsSql2012Dialect
{
  public CustomMsSq2012Dialect()
  {
    RegisterFunction("AddDays",
      new SQLFunctionTemplate(
        NHibernateUtil.DateTime,
        "dateadd(day,?2,?1)"));
    RegisterFunction("AddHours",
      new SQLFunctionTemplate(
        NHibernateUtil.DateTime,
        "dateadd(hour,?2,?1)"));
    RegisterFunction("AddMinutes",
      new SQLFunctionTemplate(
        NHibernateUtil.DateTime,
        "dateadd(minute,?2,?1)"));
    RegisterFunction("AddSeconds",
      new SQLFunctionTemplate...