核心3.0升级后，无法使用EF核心3.0添加迁移

Question

升级核心3.0后，无法在包管理器中添加迁移。这是我的错误

PM> Add-Migration UpdateAlertTable -Context OozymContext
System.Reflection.TargetInvocationException: Exception has been thrown by the target of an invocation.
 ---> System.TypeLoadException: Could not load type 'Microsoft.EntityFrameworkCore.Internal.ProductInfo' from assembly 'Microsoft.EntityFrameworkCore, Version=3.0.0.0, Culture=neutral, PublicKeyToken=adb9793829ddae60'.
   at Microsoft.EntityFrameworkCore.Design.OperationExecutor..ctor(Object reportHandler, IDictionary args)
   --- End of inner exception stack trace ---
   at System.RuntimeMethodHandle.InvokeMethod(Object target, Object[] arguments, Signature sig, Boolean constructor, Boolean wrapExceptions)
   at System.Reflection.RuntimeConstructorInfo.Invoke(BindingFlags invokeAttr, Binder binder, Object[] parameters, CultureInfo culture)
   at System.RuntimeType.CreateInstanceImpl(BindingFlags bindingAttr, Binder binder, Object[] args, CultureInfo culture)
   at System.Activator.CreateInstance(Type type, BindingFlags bindingAttr, Binder binder, Object[] args, CultureInfo culture, Object[] activationAttributes)
   at System.Activator.CreateInstance(Type type, Object[] args)
   at Microsoft.EntityFrameworkCore.Tools.ReflectionOperationExecutor..ctor(String assembly, String startupAssembly, String projectDir, String dataDirectory, String rootNamespace, String language)
   at Microsoft.EntityFrameworkCore.Tools.Commands.ProjectCommandBase.CreateExecutor()
   at Microsoft.EntityFrameworkCore.Tools.Commands.MigrationsAddCommand.Execute()
   at Microsoft.EntityFrameworkCore.Tools.Commands.CommandBase.<>c__DisplayClass0_0.<Configure>b__0()
   at Microsoft.DotNet.Cli.CommandLine.CommandLineApplication.Execute(String[] args)
   at Microsoft.EntityFrameworkCore.Tools.Program.Main(String[] args)
Exception has been thrown by the target of an invocation.

Answer 1

软件包管理器控制台中的命令已经更改。根据Nuget画廊参考。下面跟随。

Add-Migration
Drop-Database
Get-DbContext
Scaffold-DbContext
Script-Migrations
Update-Database

Answer 2

我在一个链接项目中引用了Microsoft.EntityFrameworkCore版本2.2.6，该项目具有数据库连接字符串。我升级了，它起作用了

Answer 3

在升级到3.0版后，我也遇到了同样的问题。在阅读本文后，我安装了Microsoft.EntityFrameworkCore。设计nuget软件包，问题得到解决。