值不能为空。 参数名称：connectionstring-尝试从SQLITE切换到MSSQL时

Question

当我尝试切换到在本地计算机上安装的MSSQL数据库时，我得到了这种美。

System.ArgumentNullException: Value cannot be null.
Parameter name: connectionString
   at Microsoft.EntityFrameworkCore.Utilities.Check.NotEmpty(String value, String parameterName)
   at Microsoft.EntityFrameworkCore.SqlServerDbContextOptionsExtensions.UseSqlServer(DbContextOptionsBuilder optionsBuil
der, String connectionString, Action`1 sqlServerOptionsAction)
   at MSBlog.Startup.<ConfigureServices>b__4_0(DbContextOptionsBuilder options)
   at Microsoft.Extensions.DependencyInjection.EntityFrameworkServiceCollectionExtensions.DbContextOptionsFactory[TConte
xt](IServiceProvider applicationServiceProvider, Action`2 optionsAction)
   at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteRuntimeResolver.VisitScoped(ScopedCallSite scopedCa
llSite, ServiceProvider provider)
   at Microsoft.Extensions.DependencyInjection.ServiceProvider.<>c__DisplayClass16_0.<RealizeService>b__0(ServiceProvide
r provider)
   at Microsoft.Extensions.DependencyInjection.ServiceProviderServiceExtensions.GetRequiredService(IServiceProvider prov
ider, Type serviceType)
   at Microsoft.Extensions.DependencyInjection.ServiceProviderServiceExtensions.GetRequiredService[T](IServiceProvider p
rovider)
   at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteRuntimeResolver.VisitScoped(ScopedCallSite scopedCa
llSite, ServiceProvider provider)
   at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteRuntimeResolver.VisitClosedIEnumerable(ClosedIEnume
rableCallSite closedIEnumerableCallSite, ServiceProvider provider)
   at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteRuntimeResolver.VisitTransient(TransientCallSite tr
ansientCallSite, ServiceProvider provider)
   at Microsoft.Extensions.DependencyInjection.ServiceProvider.<>c__DisplayClass16_0.<RealizeService>b__0(ServiceProvide
r provider)
   at Microsoft.Extensions.DependencyInjection.ServiceProviderServiceExtensions.GetRequiredService(IServiceProvider prov
ider, Type serviceType)
   at Microsoft.Extensions.DependencyInjection.ServiceProviderServiceExtensions.GetRequiredService[T](IServiceProvider p
rovider)
   at Microsoft.EntityFrameworkCore.Design.Internal.DbContextOperations.FindContextTypes()
   at Microsoft.EntityFrameworkCore.Design.Internal.DbContextOperations.GetContextTypes()
   at Microsoft.EntityFrameworkCore.Design.OperationExecutor.GetContextTypesImpl()
   at Microsoft.EntityFrameworkCore.Design.OperationExecutor.OperationBase.<>c__DisplayClass4_0`1.<Execute>b__0()
   at Microsoft.EntityFrameworkCore.Design.OperationExecutor.OperationBase.Execute(Action action)
Value cannot be null.
Parameter name: connectionString


"ConnectionStrings": {
    "DefaultConenction" : "Server=localhost;Database=db;User Id=user;Password=pw;Trusted_Connection=True;",
    "OldConnection": "DataSource=.\\some.db"
  },

我还将Startup.cs的AddDbContext调用更改为：

services.AddDbContext<ApplicationDbContext>(          options.UseSqlServer(Configuration.GetConnectionString("DefaultConnection")));

最后，我刚刚将新模型作为DbSets添加到ApplicationDbContext中。 我究竟做错了什么？

我运行的以dotnet ef开头的任何命令都会导致上述错误，并且我无法弄清什么是null。

这些是我正在运行的版本：

<PackageReference Include="Microsoft.AspNetCore" Version="1.1.2" />
<PackageReference Include="Microsoft.AspNetCore.Authentication.Cookies" Version="1.1.2" />
<PackageReference Include="Microsoft.AspNetCore.Diagnostics.EntityFrameworkCore" Version="1.1.2" />
<PackageReference Include="Microsoft.AspNetCore.Identity.EntityFrameworkCore" Version="1.1.2" />
<PackageReference Include="Microsoft.AspNetCore.Mvc" Version="1.1.2" />
<PackageReference Include="Microsoft.AspNetCore.StaticFiles" Version="1.1.2" />
<PackageReference Include="Microsoft.EntityFrameworkCore.Design" Version="1.1.2" PrivateAssets="All" />
<PackageReference Include="Microsoft.EntityFrameworkCore.SqlServer" Version="1.1.2" />
<PackageReference Include="Microsoft.EntityFrameworkCore.SqlServer.Design" Version="1.1.2" PrivateAssets="All" />
<PackageReference Include="Microsoft.EntityFrameworkCore.Tools" Version="1.0.0-msbuild3-final" PrivateAssets="All" />
<PackageReference Include="Microsoft.Extensions.Configuration.UserSecrets" Version="1.1.2" />
<PackageReference Include="Microsoft.Extensions.Logging.Debug" Version="1.1.2" />
<PackageReference Include="Microsoft.VisualStudio.Web.BrowserLink" Version="1.1.2" />

请帮忙！

Answer 1

在配置中更正DefaultConenction的拼写。