C# ASP.NET核心WebApi添加迁移实体框架核心

我正在尝试使用实体框架核心和AutoMapper构建一个ASP.NET核心WebApi。当我尝试使用

addmigration

时，调用的目标抛出了异常。在

Microsoft.EntityFrameworkCore.Tools.Program.Main（String[]args）

（我没有对程序类做任何更改）。我认为问题可能是程序找不到连接字符串
这是我的DataBaseContext类：

    public class DataBaseContext : DbContext
    {
        protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
        {
            IConfigurationRoot configuration = new ConfigurationBuilder()
                .SetBasePath(AppDomain.CurrentDomain.BaseDirectory)
                .AddJsonFile("appsettings.json")
                .Build();
            optionsBuilder.UseSqlServer(configuration.GetConnectionString("DataBaseContext"));
        }
        public DataBaseContext(DbContextOptions<DataBaseContext> options) : base(options)
        {
                
        }

        public DbSet<Director> Directors { get; set; }

        public DbSet<Movie> Movies { get; set; }
    }

这是Startup.cs：

public class Startup
    {
        public Startup(IConfiguration configuration)
        {
            Configuration = configuration;
        }

        public IConfiguration Configuration { get; }

        // This method gets called by the runtime. Use this method to add services to the container.
        public void ConfigureServices(IServiceCollection services)
        {
            services.AddDbContext<DataBaseContext>(opt =>
                opt.UseSqlServer("DataBaseContext"));

            var config = new AutoMapper.MapperConfiguration(c =>
            {
                c.AddProfile(new MapperProfile());
            });

            var mapper = config.CreateMapper();

            services.AddSingleton(mapper);
            services.AddSingleton<IUserService, UserService>();
            services.AddControllers();
        }

        //some code
    }
}

公共类启动
{
公共启动（IConfiguration配置）
{
配置=配置；
}
公共IConfiguration配置{get；}
//此方法由运行时调用。请使用此方法将服务添加到容器中。
public void配置服务（IServiceCollection服务）
{
services.AddDbContext（opt=>
opt.UseSqlServer（“DataBaseContext”）；
var config=new AutoMapper.MapperConfiguration（c=>
{
c、 AddProfile（新的MapperProfile（））；
});
var mapper=config.CreateMapper（）；
服务。AddSingleton（映射器）；
services.AddSingleton（）；
services.AddControllers（）；
}
//一些代码
}
}

这是someproject.csproj：

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

  <PropertyGroup>
    <TargetFramework>netcoreapp3.1</TargetFramework>
  </PropertyGroup>

  <ItemGroup>
    <PackageReference Include="AutoMapper" Version="10.1.1" />
    <PackageReference Include="Microsoft.Bcl.AsyncInterfaces" Version="5.0.0" />
    <PackageReference Include="Microsoft.EntityFrameworkCore" Version="5.0.2" />
    <PackageReference Include="Microsoft.EntityFrameworkCore.InMemory" Version="5.0.2" />
    <PackageReference Include="Microsoft.EntityFrameworkCore.Sqlite" Version="3.1.11" />
    <PackageReference Include="Microsoft.EntityFrameworkCore.SqlServer" Version="3.1.11" />
    <PackageReference Include="Microsoft.EntityFrameworkCore.Tools" Version="3.1.11">
      <PrivateAssets>all</PrivateAssets>
      <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
    </PackageReference>
    <PackageReference Include="Microsoft.VisualStudio.Web.CodeGeneration.Design" Version="3.1.4" />
  </ItemGroup>


</Project>

netcoreapp3.1
全部的
运行时间；建设；本地人；内容文件；分析仪；可传递的

因为您的项目是3.1版本，所以您的软件包

<PackageReference Include="Microsoft.EntityFrameworkCore" Version="5.0.2" />
<PackageReference Include="Microsoft.EntityFrameworkCore.InMemory" Version="5.0.2" />

不兼容

您需要将其更改为：

<PackageReference Include="Microsoft.EntityFrameworkCore" Version="3.1.11" />
<PackageReference Include="Microsoft.EntityFrameworkCore.InMemory" Version="3.1.11" />

您试过了吗？

<PackageReference Include="Microsoft.EntityFrameworkCore" Version="3.1.11" />
<PackageReference Include="Microsoft.EntityFrameworkCore.InMemory" Version="3.1.11" />