Question

我有一个ASP .Net核心应用程序，它使用sql server数据库中的现有表。由于这些表在我创建应用程序之前已经存在，为了在应用程序中构建它们的模型，我使用命令对表进行了反向设计：

Scaffold-DbContext "Server=(localdb)\mssqllocaldb;Database=Blogging;Trusted_Connection=True;" Microsoft.EntityFrameworkCore.SqlServer -OutputDir Models

使用此命令成功创建了模型，到目前为止我已经能够根据需要从数据库表中进行查询。现在，我正在为应用程序的用户注册系统工作并添加了必要的ASP .Net实体框架核心身份服务，并且作为流程的一部分，需要将所需的应用程序用户模型迁移到数据库。

我尝试首先运行（在包管理器控制台中）命令add-migration IdentityAdded -context DBContext并且出现错误：Add-Migration : A parameter cannot be found that matches parameter name 'context'。在此之后，我认为既然我还没有运行迁移，我需要运行命令Add-Migration InitialCreate，但在运行命令后，出现错误：

Exception calling "SetData" with "2" argument(s): "Type 'Microsoft.VisualStudio.ProjectSystem.VS.Implementation.Package.Automation.OAProject' in assembly 
'Microsoft.VisualStudio.ProjectSystem.VS.Implementation, Version=15.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d2940a' is not marked as serializable.

自从我最初反向设计数据库表后，是否可以再次运行迁移？可能导致问题的原因是什么？

以下是启动文件供参考：

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)
        {
            //using( var context = new ApplicationDbContext())
            //{
            //    context.Database.EnsureCreated();
            //}
            services.AddDbContext<DBContext>(options => options.UseSqlServer(Configuration.GetConnectionString("Cn")));
            services.AddMvc();

            services.AddIdentity<ApplicationUser, IdentityRole>()
    .AddEntityFrameworkStores<DBContext>()
    .AddDefaultTokenProviders();

            services.Configure<IdentityOptions>(options =>
            {
                // Password settings
                options.Password.RequireDigit = true;
                options.Password.RequiredLength = 8;
                options.Password.RequireNonAlphanumeric = false;
                options.Password.RequireUppercase = true;
                options.Password.RequireLowercase = false;
                options.Password.RequiredUniqueChars = 6;

                // Lockout settings
                options.Lockout.DefaultLockoutTimeSpan = TimeSpan.FromMinutes(30);
                options.Lockout.MaxFailedAccessAttempts = 10;
                options.Lockout.AllowedForNewUsers = true;

                // User settings
                options.User.RequireUniqueEmail = true;
            });

            services.ConfigureApplicationCookie(options =>
            {
                // Cookie settings
                options.Cookie.HttpOnly = true;
                options.ExpireTimeSpan = TimeSpan.FromMinutes(30);
                // If the LoginPath isn't set, ASP.NET Core defaults 
                // the path to /Account/Login.
                options.LoginPath = "/Account/Login";
                // If the AccessDeniedPath isn't set, ASP.NET Core defaults 
                // the path to /Account/AccessDenied.
                options.AccessDeniedPath = "/Account/AccessDenied";
                options.SlidingExpiration = true;
            });
            services.AddPaging();
        }

        // This method gets called by the runtime. Use this method to configure the HTTP request pipeline.
        public void Configure(IApplicationBuilder app, IHostingEnvironment env)
        {
            if (env.IsDevelopment())
            {
                app.UseBrowserLink();
                app.UseDeveloperExceptionPage();
            }
            else
            {
                app.UseExceptionHandler("/Home/Error");
            }
            //app.UseIdentity(); //will be deprecated
            AuthAppBuilderExtensions.UseAuthentication(app);
            app.UseStaticFiles();

            app.UseMvc(routes =>
            {
                routes.MapRoute(
                    name: "default",
                    template: "{controller=resortDeals}/{action=Index}/{id?}");

            //routes.MapRoute(
            //         name: "DetailsRoute",
            //         template: "{controller=resortDeals}/{action=Details}/{id}");
        }

            );

修改

应用用户类：

 public class ApplicationUser : IdentityUser
    {

    }

Answer 1

我认为您传递给-Context的参数Add-Migration区分大小写。

此外，您用于AspNet标识的DBContext必须继承自IdentityDbContext

Answer 2

看起来他们在这里有类似的问题： Enable-Migrations Exception calling "SetData" with "2" argument(s)

Enable-Migrations installation error

或许你有这个问题：https://github.com/aspnet/EntityFramework6/issues/231

第一次运行数据库迁移时出错

修改

2 个答案: