Amin Emamiwww.aminemami.com

• Introduction• Object Relational Mapping• Persistence Framework• Sample Code• Q&A

Amin Emami

• Director of Information Technology• 10 Years of Enterprise Software

Development• Using Persistence Frameworks since

2001o EJB (Java): 2001o Hibernate (Java): 2004o NHibernate (.Net): 2005o Entity Framework: 2009

Amin Emami

Amin Emami

Architectural View

How do you map these classes to relational tables?

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• Object-Oriented: Everything is an object• Objects vs. Tables: ODBMS?• OO features• Object Types vs. DB Types• CRUD to/from database• Objects vs. tabular data• Managed Code

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• A technique to map the classes and the tables• Simplified rules

o Table per main objecto No FK, use object referenceo One-to-many relationso Association table for many-to-many relationso In a one-to-one relation, all the fields go to one

main tableo Inheritance mapping strategies

Tale per class hierarchy Table per concrete class

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Amin Emami

• Let’s take a look at the sample codeo Class Diagramo POCO classes

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• ORM library, providing a framework foro Mapping an object-oriented domain model to

relational databaseo High level persistence object handling

functions

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Some of .Net Persistence Frameworks:• NHibernate • Entity Framework• Gentle.NET• Wilson O/R • NPersist• Persistor.NET• iBATIS• Bamboo.Prevalence• etc

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Amin Emami

Amin Emami

• Class Diagram• POCO classes• Mapping files• Configurations• Transactions

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• Better object-oriented• Collection Mapping• Basic queries and object persistence is

handled by the framework• Object query language instead of SQL,

doing more complex queries• Lazy loading

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• Database independency• Transaction management• Automatic primary key generation• Automatic dirty checking• Detached object• Concurrency• Caching

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• Caching• Detached object• Concurrency• Interceptors• Batch processing• Attributes• Fluent Syntax• Database independency

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• ORM Concept• Simple ORM Techniques• Persistence Frameworks• NHibernate Key Features

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Amin Emami

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