Nhibernate

NHibernate in Action
PIERRE HENRI KUATÉ TOBIN HARRIS CHRISTIAN BAUER GAVIN KING

MANNING
Greenwich (74° w. long.)

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contents
foreword xvii preface xxi acknowledgments xxiii about this book xxv

PART 1 DISCOVERING ORM WITH NHIBERNATE ................ 1

1

Object/relational persistence in .NET 3
1.1 What is persistence? 5
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Relational databases 5 Understanding SQL 6 Using SQL in.NET applications 6 Persistence in object-oriented applications 6 Persistence and the layered architecture 7
■

1.2

Approaches to persistence in .NET
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9
■

Choice of persistence layer 9 Implementing the entities 11 Displaying entities in the user interface 13 Implementing CRUD operations 14

1.3

Why do we need NHibernate?
■

15

The paradigm mismatch 15 Units of work andconversations 16 Complex queries and the ADO.NET Entity Framework 18

ix

x

CONTENTS

1.4 1.5

Object/relational mapping
What is ORM? 21
■

21

Why ORM? 21

Summary

23

2

Hello NHibernate! 24
2.1 “Hello World” with NHibernate
■ ■

25

Installing NHibernate 25 Create a new Visual Studio project 25 Creating the Employee class 26 Setting up the database 27 Creating anEmployee and saving to the database 27 Loading an Employee from the database 29 Creating a mapping file 29 Configuring your application 31 Updating an Employee 32 Running the program 33
■ ■ ■ ■

2.2

Understanding the architecture
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33
■

The core interfaces 35 Callback interfaces 36 Extension interfaces 37

Types 37

2.3

Basic configuration

38
■

Creating a SessionFactory38 database access 41

Configuring the ADO.NET

2.4 2.5

Advanced configuration settings Summary 48

44
■

Using the application configuration file 44

Logging 47

PART 2 NHIBERNATE DEEP DIVE ..................................... 49

3

Writing and mapping classes 51
3.1 The CaveatEmptor application
Analyzing the business domain 52 domain model 53
■

52
The CaveatEmptor3.2

Implementing the domain model
■ ■

55

Addressing leakage of concerns 55 Transparent and automated persistence 55 Writing POCOs 56 Implementing POCO associations 58 Adding logic to properties 61
■

3.3

Defining the mapping metadata
Mapping using XML 63
■

63

Attribute-oriented programming 65

CONTENTS

xi

3.4

Basic property and class mappings
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66...