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
我想进行代码优先迁移，但不确定如何正确设置.我将 Migrator.EF6.Tools 添加到我的项目中.
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 Enable-Migrations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:UsersSomeUser.nugetpackagesentityframework6.1.3 oolsEntityFramework.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:UsersSomeUser.nugetpackagesentityframework6.1.3 oolsEntityFramework.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:UsersSomeUser.nugetpackagesentityframework6.1.3 oolsEntityFramework.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
这里真正的问题是存在不同的 EF风味".只需转到 EF 根文档并查看差异:
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/aspnet/core/data/ef-mvc/migrations 迁移命令在 .Net Core 中发生了很大变化，我推荐另请访问: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这是我在 EF 6 和 .NET Core 中使用迁移的秘诀:
1st.- 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
2nd.- 在您的项目中创建上下文，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
}
3rd.- 添加迁移:
转到项目文件夹，从 cmd 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.- 更新你的数据库:4.a.- 在 docker 中 -> 您可以运行项目(完全使用 Docker)，迁移将在第一次使用 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:(它将使用为该环境配置的连接字符串)
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
希望对你有帮助.
胡安