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EF Code First数据库连接配置

　　前面几节，使用的都是通过EF Code First创建的新数据库，接下来，将开始使用已存在的数据库。

　　1、使用配置文件设置数据库连接

　　App.config

　　数据库连接字符串的name与Data中NorthwindContext.cs类名相同

<?xml version="1.0" encoding="utf-8"?><configuration> <configSections>  <section name="entityFramework" type="System.Data.Entity.Internal.ConfigFile.EntityFrameworkSection, EntityFramework, Version=4.3.1.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" /> </configSections> <connectionStrings> <add name="NorthwindContext" connectionString="Data Source=(local); Database=Northwind; User ID=sa; Password=1;" providerName="System.Data.SqlClient"/> </connectionStrings></configuration>　　Data中NorthwindContext.cs

1 using System; 2 using System.Collections.Generic; 3 using System.Linq; 4 using System.Text; 5 6 using System.Data.Entity; 7 8 using Northwind.Domain.Entities; 9 using Northwind.Domain.Mapping;10 11 namespace Northwind.Data12 {13 public class NorthwindContext : DbContext14 {15 public DbSet<Category> Categories { get; set; }16 public DbSet<Product> Products { get; set; }17 public DbSet<Supplier> Suppliers { get; set; }18 19 protected override void OnModelCreating(DbModelBuilder modelBuilder)20 {21 modelBuilder.Configurations.Add(new CategoryMap());22 modelBuilder.Configurations.Add(new ProductMap());23 modelBuilder.Configurations.Add(new SupplierMap());24 }25 }26 }　　执行成功后，创建的数据库如下图：

　　2、使用构造函数指定数据库

　　NorthwindContext.cs

1 using System; 2 using System.Collections.Generic; 3 using System.Linq; 4 using System.Text; 5 6 using System.Data.Entity; 7 8 using Northwind.Domain.Entities; 9 using Northwind.Domain.Mapping;10 11 namespace Northwind.Data12 {13 public class NorthwindContext : DbContext14 {15 public NorthwindContext()16 { }17 18 public NorthwindContext(string databaseName)19 : base(databaseName)20 {21 22 }23 24 public DbSet<Category> Categories { get; set; }25 public DbSet<Product> Products { get; set; }26 public DbSet<Supplier> Suppliers { get; set; }27 public DbSet<User> Users { get; set; }28 public DbSet<Role> Roles { get; set; }29 30 protected override void OnModelCreating(DbModelBuilder modelBuilder)31 {32 modelBuilder.Configurations.Add(new CategoryMap());33 modelBuilder.Configurations.Add(new ProductMap());34 modelBuilder.Configurations.Add(new SupplierMap());35 modelBuilder.Configurations.Add(new UserMap());36 modelBuilder.Configurations.Add(new RoleMap());37 }38 }39 }　　Program.cs

using (NorthwindContext db = new NorthwindContext("Northwind")){}　　3、使用构造函数指定数据库连接字符串

　　App.config

1 <?xml version="1.0" encoding="utf-8"?> 2 <configuration> 3 <configSections> 4  5 <section name="entityFramework" type="System.Data.Entity.Internal.ConfigFile.EntityFrameworkSection, EntityFramework, Version=4.3.1.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" /> 6 </configSections> 7 <connectionStrings> 8 <add name="NorthwindConnectionString" connectionString="Data Source=(local); Database=Northwind; User ID=sa; Password=1;" providerName="System.Data.SqlClient"/> 9 </connectionStrings>10 </configuration>　　NorthwindContext.cs

1 using System; 2 using System.Collections.Generic; 3 using System.Linq; 4 using System.Text; 5 6 using System.Data.Entity; 7 8 using Northwind.Domain.Entities; 9 using Northwind.Domain.Mapping;10 11 namespace Northwind.Data12 {13 public class NorthwindContext : DbContext14 {15 public NorthwindContext()16 : base("name=NorthwindConnectionString")17 { }18 19 public DbSet<Category> Categories { get; set; }20 public DbSet<Product> Products { get; set; }21 public DbSet<Supplier> Suppliers { get; set; }22 public DbSet<User> Users { get; set; }23 public DbSet<Role> Roles { get; set; }24 25 protected override void OnModelCreating(DbModelBuilder modelBuilder)26 {27 modelBuilder.Configurations.Add(new CategoryMap());28 modelBuilder.Configurations.Add(new ProductMap());29 modelBuilder.Configurations.Add(new SupplierMap());30 modelBuilder.Configurations.Add(new UserMap());31 modelBuilder.Configurations.Add(new RoleMap());32 }33 }34 }