Question

我有一个控制台应用程序，我设法使用Code First创建数据库但我不能播种任何数据。我在Package Manager Console中使用update-database来完成它。请帮忙。我正在寻找几个小时。这是我的代码：

/ Models / ApplicationDbContext class：

namespace ToDoApp.Models
{
    public class ApplicationDbContext : DbContext
    {
        public ApplicationDbContext()
           : base("ToDoApp")
        {
        Database.SetInitializer(new ApplicationDbInitializer());
        }

        public DbSet<TestModel> Tests { get; set; }
    }

}

/ Models / ApplicationDbInitializer类：

 public class ApplicationDbInitializer : DropCreateDatabaseAlways<ApplicationDbContext>
 {
    protected override void Seed(ApplicationDbContext context)
    {
        context.Tests.AddOrUpdate(new TestModel()
        {
            Description = "Test1"
        });
       base.Seed(context);
    }
 }

/ Models / TestModel类：

public class TestModel
{
    [Key]
    public int Id { get; set; }

    public string Description { get; set; }
}

/程序类：

    class Program
    {
    static void Main(string[] args)
        {
        Console.ReadLine();
        }
    }

/App.config:

<?xml version="1.0" encoding="utf-8"?>
<configuration>
  <configSections>
    <section name="entityFramework" type="System.Data.Entity.Internal.ConfigFile.EntityFrameworkSection, EntityFramework, Version=6.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" requirePermission="false" />
    <!-- For more information on Entity Framework configuration, visit http://go.microsoft.com/fwlink/?LinkID=237468 -->
  </configSections>
  <startup>
    <supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.5.1" />
  </startup>
  <entityFramework>
    <defaultConnectionFactory type="System.Data.Entity.Infrastructure.SqlConnectionFactory, EntityFramework" />
    <providers>
      <provider invariantName="System.Data.SqlClient" type="System.Data.Entity.SqlServer.SqlProviderServices, EntityFramework.SqlServer" />
    </providers>
    <!--<contexts>
      <context type="ToDoApp.Models.ApplicationDbContext, ToDoApp">
        <databaseInitializer type="ToDoApp.Models.ApplicationDbInitializer, ToDoApp" />  
      </context>
    </contexts>--> <!-- This don't work -->
 </entityFramework>
  <runtime>
    <assemblyBinding xmlns="urn:schemas-microsoft-com:asm.v1">
  <dependentAssembly>
    <assemblyIdentity name="Newtonsoft.Json" publicKeyToken="30ad4fe6b2a6aeed" culture="neutral" />
    <bindingRedirect oldVersion="0.0.0.0-11.0.0.0" newVersion="11.0.0.0" />
  </dependentAssembly>
</assemblyBinding>
  </runtime>
  <appSettings>
   <add key="DatabaseInitializerForType ToDoApp.Models.ApplicationDbContext, ToDoApp"
     value="ToDoApp.Models.ApplicationDbInitializer, ToDoApp" />
  </appSettings> <!-- This don't work also -->
</configuration>

Answer 1

update-database将运行迁移种子（）。您的代码适用于初始化程序 Seed（），它仅在创建数据库时运行。有关差异的说明，请参阅here。

由于您使用DropCreateDatabaseAlways，因此只要模型发生变化，它就会运行。你可以删除数据库。否则，强制进行模型更改，然后在代码中访问上下文或在启动时调用context.Database.Initialize()。

EF Code First无法播种数据库[控制台应用]

1 个答案: