Entity Framework NET Framework ADO NET Data Set

なぜ Entity Framework なのか? . NET Framework は、様々なデータ アクセス テクノロジを提供しています ADO. NET Data. Set LINQ to SQL Entity Framework 5 おさらい

多対多エンティティへの登録 using (var context = new Tech. Ed 10 Entities()) { var teched. Project = new Project { Name = "Tech. Ed Project", Members = { new Member { Name = "Fukui", Tweet. Id = "@afukui"}, new Member { Name = "Moriya", Tweet. Id = "@hmoriya 55"} } }; context. Projects. Add. Object(teched. Project); context. Save. Changes(); } 11

遅延ロード var q = from p in context. Projects select p; foreach (var project in q) { Console. Write. Line(project. Name); foreach (var member in project. Members) { Console. Write. Line("t" + member. Name + " (" + member. Tweet. Id + ")" ); } } 12

Table-Per-Type 継承 15

Table-Per-Hierarchy 継承 16

自動生成される SQL の一部 (Table-Per-Type 継承の例) CREATE TABLE [dbo]. [Parties] ( [Id] int IDENTITY(1, 1) NOT NULL, [Name] nvarchar(max) NOT NULL ); GO CREATE TABLE [dbo]. [Parties_Organization] ( [Location] nvarchar(max) NOT NULL, [Id] int NOT NULL ); GO CREATE TABLE [dbo]. [Parties_Person] ( [Age] int NOT NULL, [Id] int NOT NULL ); GO 18

DEMO EF 4 状態管理 Entity. State の確認

Entity. State の確認 using (var context = new Tech. Ed 10 Entities()) { //オブジェクトの追加、更新処理をここで行う … Console. Write. Line( context. Object. State. Manager. Get. Object. State. Entry( teched. Project). State); } 22

自己追跡エンティティ (クライアント側) var svc = new Channel. Factory<ICustomer. Service>( binding, address). Create. Channel(); var customers = svc. Get. Customers(); var products = svc. Get. Products(); var customer = customers. Where( c => c. Customer. ID == "ALFKI"). First. Or. Default(); customer. Contact. Name = "Bill Gates"; customer. Orders. Add(new. Order); svc. Update. Customer(customer); 35

自己追跡エンティティ (サービス側) using (Northwind. Entities context = new Northwind. Entities()) { context. Customers. Apply. Changes(customer); context. Save. Changes(); } 36

Compiled. Query クラス static readonly Func<Teched 10 Entities, string, IQueryable<Project>> my. Query = Compiled. Query. Compile<Teched 10 Entities, string, IQueryable<Project>>( (ctx, member. Name) => from p in ctx. Projects where p. Members. Any( m => m. Name == member. Name) orderby p. Name select p); private static void Compiled. Query. Smaple(){ using (var context = new Teched 10 Entities()){ var projects = my. Query. Invoke(context, "Atsushi Fukui"); … 40

パフォーマンス Tips //読み取り専用カーソルの利用 Context. Customers. Merge. Option = Merge. Option. No. Tracking; //一括読み込み Context. Option. Lazy. Load. Enabled = false; context. customers. Include("Orderes"); //ストアド プロシージャの利用 context. Execute. Store. Command( "UPDATE T set a = {0}", params); 41

DEMO Code First CTP 4 の機能

POCO クラス public class Book { public string ISBN { get; set; } public string Title { get; set; } public Date. Time First. Published { get; set; } public bool Is. Fiction { get; set; } public virtual Publisher { get; set; } public virtual Author { get; set; } } 44

Db. Context public class Simple. Book. Catalog : Db. Context { public Simple. Book. Catalog(Db. Model model) : base(model) { } public } 45 Db. Set<Book> Books { get; set; } Db. Set<Person> People { get; set; } Db. Set<Author> Authors { get; set; } Db. Set<Publisher> Publishers { get; set; }

Model. Builder var builder = new Model. Builder(); builder. Configurations. Add( new Book. Configuration()); builder. Entity<Person>(); builder. Entity<Publisher>(). Property( p => p. Name). Is. Required(). Has. Max. Length(50); var model = builder. Create. Model(); 46

Entity. Configuration<T> public class Book. Configuration : Entity. Configuration<Book> { public Book. Configuration() { this. Has. Key(b => b. ISBN); this. Property(b => b. Title). Is. Required(); this. Has. Required(b => b. Author). With. Many(a => a. Books); } } 47

エンティティの追加 using (var context = new Simple. Book. Catalog(model)) { var book = new Book { ISBN = "2222", Title = "Intro to Code First", First. Published = Date. Time. Today, Author = new Author { First. Name = “Atsushi”, Last. Name = "Fukui" }, Publisher = new Publisher { Name = "EF Books" } }; context. Books. Add(book); context. Save. Changes(); 48

リファレンス n 層アプリケーションのパターン http: //msdn. microsoft. com/ja-jp/magazine/ee 321569. aspx n 層アプリケーションで回避すべきアンチパターン http: //msdn. microsoft. com/ja-jp/magazine/dd 882522. aspx EF 4 による n 層アプリケーションの構築 http: //msdn. microsoft. com/ja-jp/magazine/ee 335715. aspx ADO. NET team blog （英語） http: //blogs. msdn. com/b/adonet/ 53