Microsoft Entity Framework v1.1 over Oracle Database

1. MicrosoftEntity Framework v1.1overOracle Database Erez Harari Sela Technology Center http://blogs.microsoft.co.il/blogs/erezh/ erezh@sela.co.il

2. Agenda • Using data in applications • Entity Framework WH questions • Using EF • Designing a model • Querying a model • Working with the model • Data binding support • What else is there • Future of EF

3. Storing application data • Almost all application stores data • Data is mostly stored in relation DBs • Data stored in tables • Related data is retrievable via views • Data is stored in a normalized manner • Business-Logic sometimes “leak” to the DB

4. Modeling the data • Applications support a more comprehensive model for data – Object Oriented Model • Class & Object (Entity type & instance) • Properties • Inheritance • Complex data-types

5. Combining the two • Mapping relational to OO can be sometimes problematic • Write code to load tables into classes • Write code to load Master-Detail relations • Write code to handle Create/Update/Delete (CUD) • Apply appropriate techniques to load & persist inheritance relations • Apply business logic to compute data after loading • We had semi-solutions for some of these issues (Typed Datasets) • We had 3rd party solutions – O/R (Object-Relational) Mapping tools

6. What Is Entity Framework? • An O/R Mapper • The next layer in Ado.Net • An entity model-driven architecture • The first step in an entity-aware data platform

7. Why Use Entity Framework? • Why couple your data and your entities? • Why write a DAL every time? • Why learn different types of SQL syntaxes? • Why work hard trying to handle inherited entities?

8. Where can we find EF? • Part of Visual Studio 2008 SP1 • No special project type is required

9. How does EF work? DevArttm dotConnect for Oracle

10. Just a taste DEMO

11. The Conceptual model • Conceptual model is based on Entity Model • Define entity types • Group inherited types to an entity set • Associate entities (1:1, 1:N, N:M)

12. The Storage model • Defines different types of relational data sources: • Table • View • Stored Procedure • Native SQL • Define functions for create / update / delete (CUD) • Use existing Stored-Procedures • Native SQL • Import SP that retrieve Entities or Simple types

13. Conceptual-Storage Mapping • Map entity to storage (table, SP…) • Allow filtering source data • Support mapping single entity to multiple storage sources • Map CUD functions to SP or SQL instead of auto-generated queries • Support concurrency through original values • Support result binding to query output

14. Building a model DEMO

15. Querying EF - eSQL • Brand new query language • Allow un-typed references – no compilation check • Can leverage inheritance and collections • Useful for dynamic query building Employees model = new Employees(); var query = model.CreateQuery<Person>( @"Select VALUE p From Employees.Person as p Where p.Age > @age"); query.Parameters.Add(new ObjectParameter("age", 30)); foreach (Person p in query) { Console.WriteLine(p.FirstName + " " + p.LastName ); }

16. Querying EF – Extension Methods • Query model against EDM • Typed references, using lambda expressions • Compiler verified • Can return anonymous types • A bit hard to read Employees model = new Employees(); int age = 30; var query = model.Person. Where(p => p.Age > age). Select(item => new { FullName = item.FirstName + " " + item.LastName }); foreach (var p in query) { Console.WriteLine(p.FullName); }

17. Querying EF – LINQ to Entities • LINQ-based syntax • Compiles as set of extension methods • Much more readable than extension methods • Makes building enhanced queries a lot easier Employees model = new Employees(); int age = 30; var query = from p in model.Person where p.Age > age select new { FullName = p.FirstName + " " + p.LastName}; foreach (var p in query) { Console.WriteLine(p.FullName); } 101 LINQ Samples http://tinyurl.com/62j6sb

18. from p in model.Person where p.Age > age select new {FullName = p.FirstName + " " + p.LastName}; model.Person. Where(p => p.Age > age). Select(p => new {FullName = p.FirstName + " " + p.LastName }); model.CreateQuery<DbDataRecord>( @"Select p.FirstName + "" "" + p.LastName as FullName From Employees.Person as p Where p.Age > @age"); Query tree structure SELECT 1 AS [C1], [Extent1].[FirstName] + ' ' + [Extent1].[LastName] AS [C2] FROM [dbo].[Person] AS [Extent1] WHERE [Extent1].[Age] > @age Querying - behind the scenes

19. Querying the model DEMO

20. Transactions and Concurrency • Transactions • All updates executed in .SaveChanges() are wrapped in a transaction • Fully integrated with System.Transactions • Supports explicitly transaction usage • Concurrency • Uses Ado.Net Optimistic concurrency checks (off by default) • Using non-default update & delete queries (Native-SQL, SP…) allows access to current & original data

21. Working with layers • EF objects can be detached from & attached to a context • EF objects support XML serialization • XmlSerializer • DataContractSerializer • Can be consumed through different service types: • ASP.NET Web Services • WCF Services • Ado.Net Data Services (also support JSON serialization)

22. Summary • No more need to write DAL code • Conceptual model satisfied using EDM • CRUD operations support with no additional code needed • Can be LINQed and queried in various ways • Conceals, but doesn’t prevent – you can still use your DB code (SQL / SP) if required to

23. Resources • ADO.NET Entity Framework • Data platform developer centerhttp://msdn.microsoft.com/en-us/data/aa937723.aspx • Ado.Net team Bloghttp://blogs.msdn.com/adonet • Forumhttp://forums.microsoft.com/msdn/ShowForum.aspx?ForumID=533&SiteID=1 • ADO.NET Entity Framework V2 Designhttp://blogs.msdn.com/efdesign • Contact Me • http://blogs.microsoft.co.il/blogs/erezh • erezh@sela.co.il