如何使用ASP.NET Core设置EF6迁移 [英] How to setup EF6 Migrations with ASP.NET Core

问题描述

我正在尝试采用Jimmy Bogard的 ContosoUniversityCore项目

I am trying to adopt Jimmy Bogard's ContosoUniversityCore project

我想先进行代码迁移，但不确定如何正确设置它. 我在项目中添加了Migrator.EF6.Tools.

I would like to do code first migrations, but not sure how to properly set it up. I added Migrator.EF6.Tools to my project.

当我运行启用迁移时 我收到此错误:

When I run Enable-Migrations I get this error:

Exception calling "SetData" with "2" argument(s): "Type 'Microsoft.VisualStudio.ProjectSystem.VS.Implementation.Package.Automation.OAProject' in assembly 'Microsoft.VisualStudio.ProjectSystem.VS.Implementation, Version=14.1.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a' is not 
marked as serializable."
At C:\Users\SomeUser\.nuget\packages\entityframework\6.1.3\tools\EntityFramework.psm1:718 char:5
+     $domain.SetData('project', $project)
+     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    + CategoryInfo          : NotSpecified: (:) [], MethodInvocationException
    + FullyQualifiedErrorId : SerializationException

Exception calling "SetData" with "2" argument(s): "Type 'Microsoft.VisualStudio.ProjectSystem.VS.Implementation.Package.Automation.OAProject' in assembly 'Microsoft.VisualStudio.ProjectSystem.VS.Implementation, Version=14.1.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a' is not 
marked as serializable."
At C:\Users\SomeUser\.nuget\packages\entityframework\6.1.3\tools\EntityFramework.psm1:719 char:5
+     $domain.SetData('contextProject', $contextProject)
+     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    + CategoryInfo          : NotSpecified: (:) [], MethodInvocationException
    + FullyQualifiedErrorId : SerializationException

Exception calling "SetData" with "2" argument(s): "Type 'Microsoft.VisualStudio.ProjectSystem.VS.Implementation.Package.Automation.OAProject' in assembly 'Microsoft.VisualStudio.ProjectSystem.VS.Implementation, Version=14.1.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a' is not 
marked as serializable."
At C:\Users\SomeUser\.nuget\packages\entityframework\6.1.3\tools\EntityFramework.psm1:720 char:5
+     $domain.SetData('startUpProject', $startUpProject)
+     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    + CategoryInfo          : NotSpecified: (:) [], MethodInvocationException
    + FullyQualifiedErrorId : SerializationException

System.NullReferenceException: Object reference not set to an instance of an object.
   at System.Data.Entity.Migrations.Extensions.ProjectExtensions.GetPropertyValue[T](Project project, String propertyName)
   at System.Data.Entity.Migrations.MigrationsDomainCommand.GetFacade(String configurationTypeName, Boolean useContextWorkingDirectory)
   at System.Data.Entity.Migrations.EnableMigrationsCommand.FindContextToEnable(String contextTypeName)
   at System.Data.Entity.Migrations.EnableMigrationsCommand.<>c__DisplayClass2.<.ctor>b__0()
   at System.Data.Entity.Migrations.MigrationsDomainCommand.Execute(Action command)
Object reference not set to an instance of an object.

推荐答案

此处的真正问题是存在不同的EF风味".只需转到EF根文档并查看其中的区别:

The real issue here is that there are different EF "flavours". Just go to EF root documentation and see the differences:

• EF(根文档文件夹): https://docs.microsoft.com/en -us/ef/
• EF 6迁移命令: https://dzone.com/articles/ef-migrations-命令
• EF Core 迁移命令: https://docs.microsoft.com/en -us/ef/core/miscellaneous/cli/dotnet

• EF (root documentation folder): https://docs.microsoft.com/en-us/ef/
• EF 6 migrations commands: https://dzone.com/articles/ef-migrations-command
• EF Core migrations commands: https://docs.microsoft.com/en-us/aspnet/core/data/ef-mvc/migrations
• Migration Commands has changed a lot in .Net Core I recommend to
  visit also: https://docs.microsoft.com/en-us/ef/core/miscellaneous/cli/dotnet

这是在EF 6和.NET Core中使用迁移的食谱:

第一-您必须将这些行添加到 .csproj :

1st.- You must add these lines to the .csproj:

<ItemGroup>
    <DotNetCliToolReference Include="Microsoft.VisualStudio.Web.CodeGeneration.Tools" Version="1.0.1" />
    <DotNetCliToolReference Include="Microsoft.EntityFrameworkCore.Tools.DotNet" Version="1.0.1" />
</ItemGroup>

注意:版本已更改

第二.-在项目中创建上下文，如下所示:

public class YourContext : DbContext
{
    #region Constructors

    public YourContext()
    {
    }

    public YourContext(DbContextOptions options) : base(options)
    {

    }

    #region DbSets  // YOUR DB SETS GO HERE...
    #endregion DbSets

    #region OnConfiguring // THIS HELPED ME A LOT:
    protected override void OnConfiguring(DbContextOptionsBuilder options)
    {
        // In order to be able to create migrations and update database:
        if (!options.IsConfigured)
        {
            options.UseSqlServer("YourLocalConnectionStringShouldBeHere");
        }
        base.OnConfiguring(options);
    }
    #endregion

    #region Model Creating

    protected override void OnModelCreating(ModelBuilder modelBuilder)
    {
       // Your Model Crerating Stuff
    }

    #endregion Model Creating
}

第三名-添加迁移:

转到项目文件夹，然后从cmd 中键入:

Go to the project folder and, from cmd, type:

dotnet ef migrations add [NameOFYourMigrationGoesHere] -c YourContext

注意:不要忘记将创建的文件添加到源代码管理，这不是自动完成的

NOTE: Don't forget to add created files to source control, that's not done auto-magically

4rd.- 更新您的数据库: 4.a.- 在Docker ->中，您可以运行项目(完全使用Docker)，并且迁移将在首次使用Context时应用.

4rd.- UPDATE YOUR DB's: 4.a.- In docker -> You can run the project (entirely with Docker) and the migration would be applied at the first Context usage.

注意:(它将在该环境中使用配置的连接字符串)

note: (It will use the configured connection string for that environment)

4.b.- 您的本地数据库->编辑在ConfigurationContext.OnConfigure中硬编码的连接字符串并运行(从cmd控制台):

4.b.- Your Local DB -> Edit the Connection String hardcoded in ConfigurationContext.OnConfigure and run (from cmd console):

dotnet ef database update --context ConfigurationContext

希望对您有帮助.

胡安

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