03 EntityFramework代码优先应用于已有的数据库

1.　　创建新的数据库：

CREATE TABLE [dbo].[Blogs] ( 
    [BlogId] INT IDENTITY (1, 1) NOT NULL, 
    [Name] NVARCHAR (200) NULL, 
    [Url]  NVARCHAR (200) NULL, 
    CONSTRAINT [PK_dbo.Blogs] PRIMARY KEY CLUSTERED ([BlogId] ASC) 
); 
 
CREATE TABLE [dbo].[Posts] ( 
    [PostId] INT IDENTITY (1, 1) NOT NULL, 
    [Title] NVARCHAR (200) NULL, 
    [Content] NTEXT NULL, 
    [BlogId] INT NOT NULL, 
    CONSTRAINT [PK_dbo.Posts] PRIMARY KEY CLUSTERED ([PostId] ASC), 
    CONSTRAINT [FK_dbo.Posts_dbo.Blogs_BlogId] FOREIGN KEY ([BlogId]) REFERENCES [dbo].[Blogs] ([BlogId]) ON DELETE CASCADE 
); 
 
INSERT INTO [dbo].[Blogs] ([Name],[Url]) 
VALUES ('The Visual Studio Blog', 'http://blogs.msdn.com/visualstudio/') 
 
INSERT INTO [dbo].[Blogs] ([Name],[Url]) 
VALUES ('.NET Framework Blog', 'http://blogs.msdn.com/dotnet/')

2.　　创建控制台程序；

3.　　映射数据模型：

　　　　添加ADO.NET Entity Data Model

　　　　选取你创建的数据库

4.　　读写数据

class Program 
{ 
    static void Main(string[] args) 
    { 
        using (var db = new BloggingContext()) 
        { 
            // Create and save a new Blog 
            Console.Write("Enter a name for a new Blog: "); 
            var name = Console.ReadLine(); 
 
            var blog = new Blog { Name = name }; 
            db.Blogs.Add(blog); 
            db.SaveChanges(); 
 
            // Display all Blogs from the database 
            var query = from b in db.Blogs 
                        orderby b.Name 
                        select b; 
 
            Console.WriteLine("All blogs in the database:"); 
            foreach (var item in query) 
            { 
                Console.WriteLine(item.Name); 
            } 
 
            Console.WriteLine("Press any key to exit..."); 
            Console.ReadKey(); 
        } 
    } 
}

5.　　自定义代码优先应用于已有的数据库

　　　　Customizing Code First to an Existing Database.

6.　　数据迁移：

　　　　Code First Migrations with an existing database.