© Copyright SELA Software & Education Labs Ltd Baruch Hirsch St. Bnei Brak Israel Microsoft Entity Framework v1.1 over Oracle Database Erez Harari Sela Technology Center

© Copyright SELA Software & Education Labs Ltd Baruch Hirsch St. Bnei Brak Israel 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

© Copyright SELA Software & Education Labs Ltd Baruch Hirsch St. Bnei Brak Israel 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

© Copyright SELA Software & Education Labs Ltd Baruch Hirsch St. Bnei Brak Israel Modeling the data Applications support a more comprehensive model for data – Object Oriented Model –Class & Object (Entity type & instance) –Properties –Inheritance –Complex data-types

© Copyright SELA Software & Education Labs Ltd Baruch Hirsch St. Bnei Brak Israel 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 3 rd party solutions – O/R (Object- Relational) Mapping tools

© Copyright SELA Software & Education Labs Ltd Baruch Hirsch St. Bnei Brak Israel 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

© Copyright SELA Software & Education Labs Ltd Baruch Hirsch St. Bnei Brak Israel 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?

© Copyright SELA Software & Education Labs Ltd Baruch Hirsch St. Bnei Brak Israel Where can we find EF? Part of Visual Studio 2008 SP1 No special project type is required

© Copyright SELA Software & Education Labs Ltd Baruch Hirsch St. Bnei Brak Israel How does EF work? DevArt tm dotConnect for Oracle DevArt tm dotConnect for Oracle

© Copyright SELA Software & Education Labs Ltd Baruch Hirsch St. Bnei Brak Israel DEMO Just a taste

© Copyright SELA Software & Education Labs Ltd Baruch Hirsch St. Bnei Brak Israel 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)

© Copyright SELA Software & Education Labs Ltd Baruch Hirsch St. Bnei Brak Israel 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

© Copyright SELA Software & Education Labs Ltd Baruch Hirsch St. Bnei Brak Israel 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

© Copyright SELA Software & Education Labs Ltd Baruch Hirsch St. Bnei Brak Israel DEMO Building a model

© Copyright SELA Software & Education Labs Ltd Baruch Hirsch St. Bnei Brak Israel 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 VALUE p From Employees.Person as p Where p.Age query.Parameters.Add(new ObjectParameter("age", 30)); foreach (Person p in query) { Console.WriteLine(p.FirstName + " " + p.LastName ); } Employees model = new Employees(); var query = model.CreateQuery VALUE p From Employees.Person as p Where p.Age query.Parameters.Add(new ObjectParameter("age", 30)); foreach (Person p in query) { Console.WriteLine(p.FirstName + " " + p.LastName ); }

© Copyright SELA Software & Education Labs Ltd Baruch Hirsch St. Bnei Brak Israel 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); } 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); }

© Copyright SELA Software & Education Labs Ltd Baruch Hirsch St. Bnei Brak Israel 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); } 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 LINQ Samples

© Copyright SELA Software & Education Labs Ltd Baruch Hirsch St. Bnei Brak Israel Querying - behind the scenes

© Copyright SELA Software & Education Labs Ltd Baruch Hirsch St. Bnei Brak Israel DEMO Querying the model

© Copyright SELA Software & Education Labs Ltd Baruch Hirsch St. Bnei Brak Israel 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

© Copyright SELA Software & Education Labs Ltd Baruch Hirsch St. Bnei Brak Israel 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)

© Copyright SELA Software & Education Labs Ltd Baruch Hirsch St. Bnei Brak Israel 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

© Copyright SELA Software & Education Labs Ltd Baruch Hirsch St. Bnei Brak Israel Resources ADO.NET Entity Framework –Data platform developer center –Ado.Net team Blog –Forum &SiteID=1 &SiteID=1 ADO.NET Entity Framework V2 Design Contact Me –

© Copyright SELA Software & Education Labs Ltd Baruch Hirsch St. Bnei Brak Israel Linq2Sql VS Linq2EF LINQ to EntitiesLINQ to SQLFeature Y *YLanguage Integrated Database Queries YYEntity Inheritance YNSingle Entity From Multiple Tables YNMany-to-Many (No payload) YN (currently)Works with 3 rd party DBMS N (in V1.0)YSupports POCO (Plain Old CLR Objects) * Only queries than can be translated to SQL