创建数据库迁移时出错

Question

我尝试使用以下命令创建数据库迁移：

dotnet ef migrations add Initial

但每次我收到此错误：

不幸的是，由于这个错误，我不能再进步了，这里的问题是什么？ 这就是我如何配置连接字符串：

首先在appsettings.json中：

{
  "Data": {
        "SportStoreProducts": {
            "ConnectionStrings":"Server(localdb)\MSSQLLocalDB;Database=SportsStore;Trusted _Connection=True;MultipleActiveResultSets=true" 
        } 
    }
}

然后在启动时：

 public class Startup
{
    // This method gets called by the runtime. Use this method to add services to the container.
    // For more information on how to configure your application, visit https://go.microsoft.com/fwlink/?LinkID=398940
    public Startup(IConfiguration configuration) => Configuration = configuration;

    public IConfiguration Configuration { get; }

    public void ConfigureServices(IServiceCollection services)
    {
        services.AddDbContext<ApplicationDbContext>(
            options => options.UseSqlServer(Configuration["Data:SportStoreProducts:ConnectionString"]));

我不确定EF的版本，这是我在SportStore.csproj中添加软件包的方式：

<Project Sdk="Microsoft.NET.Sdk.Web">

<PropertyGroup>
<TargetFramework>netcoreapp2.0</TargetFramework>
</PropertyGroup>

<ItemGroup>
<PackageReference Include="Microsoft.AspNetCore.All" Version="2.0.7" />
<PackageReference Include="Microsoft.VisualStudio.Web.CodeGeneration.Design" 
Version="2.0.3" />
<DotNetCliToolReference Include="Microsoft.EntityFrameworkCore.Tools.DotNet" 
Version="2.0.0" />
</ItemGroup>

<ItemGroup>
<Folder Include="wwwroot\" />

    

从这个文件夹中，我运行命令提示符：

C:\Users\Mohsen\Google Drive\ASP.MVC Projects\SportsStore\SportsStore

我的DbContext类被调用：

ApplicationDbContext