Asp.net 实体框架核心迁移工具发布Visual Studio 2019

生成数据库迁移时，我遇到以下错误：-

命令提示：-

C:Shop\eWebShop\Web>dotnet ef migrations add "InitialDatabase" --context WebContext -p ../Persistence/Persistence.csproj -o Data/Migrations

错误：-

Unable to create an object of type 'WebContext'. For the different patterns supported at design time, see https://go.microsoft.com/fwlink/?linkid=851728

已通过包管理器控制台尝试：-

命令：-

Add-Migration InitialDatabase -Context WebContext -p Persistence -o Data/Migrations

错误：-

Add-Migration : The term 'Add-Migration' is not recognized as the name of a cmdlet, function, script file, or operable program. Check the spelling of the name, or if a path 
was included, verify that the path is correct and try again.
At line:1 char:1
+ Add-Migration InitialDatabase -Context WebContext -p Persistence -o D ...
+ ~~~~~~~~~~~~~
    + CategoryInfo          : ObjectNotFound: (Add-Migration:String) [], CommandNotFoundException
    + FullyQualifiedErrorId : CommandNotFoundException

如果您使用的是.NET Core 3

您可能需要从PMC运行install命令

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我认为您缺少一些程序包引用，请确保您在.csproj文件中包含了所有这些程序包引用

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您使用的是什么版本的.net core？