为什么我的实体框架核心数据库优先模型自定义更改在重新搭建脚手架后消失了？ 任何解决方案

Question

我正在使用 ASP.Net Core 2.1 并且我遇到了一个问题。 我一直致力于实现数据库优先应用程序。 最初的 Scaffold-DbContext 命令工作得很好，并正确创建了我的所有实体。 之后，我对模型文件进行了一些更改以进行验证。 我的 DBA 对 DB 进行了新的更改，因此我重新构建了 DB。 然后我注意到 re-scaffold 覆盖了我添加到所有模型文件中的所有自定义代码。 有什么方法可以让我重新搭建数据库，但那只会更改 DBA 在 ASP.Net Core DB First Approach 中更改的那些文件？ 每次我都面临这个问题。 我使用以下命令重新搭建脚手架：

Scaffold-DbContext "Server=192.168.46.101;Database=DBNAME;User Id=USERID;Password=PASSWORD" Microsoft.EntityFrameworkCore.SqlServer -ContextDir Data -OutputDir Models -UseDatabaseNames -force

我的自定义添加注释到模型：

    //Custom Annotation
    [Key]
    public int COLORCODE { get; set; }

    //Custom Validation
    [Required(ErrorMessage = "Color Name can not be empty")]
    public string COLOR { get; set; }

    public string REMARKS { get; set; }

重新搭建脚手架后，我的代码如下：

    public int COLORCODE { get; set; }
    public string COLOR { get; set; }
    public string REMARKS { get; set; }

我的 Program.cs 文件：

public class Program
{
    public static void Main(string[] args)
    {
        CreateWebHostBuilder(args).Build().Run();
    }

    public static IWebHostBuilder CreateWebHostBuilder(string[] args) =>
        WebHost.CreateDefaultBuilder(args)
            .ConfigureLogging((hostingContext, logging) =>
            {
                logging.AddConfiguration(hostingContext.Configuration.GetSection("Logging"));
                logging.AddConsole();
                logging.AddDebug();
                logging.AddEventSourceLogger();
                logging.AddNLog();
            })
            .UseStartup<Startup>();
}

我的 Startup.cs 文件：

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.ConfigureApplicationCookie(options =>
        {
            options.AccessDeniedPath = new PathString("/Administrator/AccessDenied");
        });

        services.Configure<CookiePolicyOptions>(options =>
        {
            // This lambda determines whether user consent for non-essential cookies is needed for a given request.
            // options.CheckConsentNeeded = context => true;
            options.MinimumSameSitePolicy = SameSiteMode.None;
        });

        services.AddDbContext<Context>(options =>
            options.UseSqlServer(
                Configuration.GetConnectionString("ConnectionName")));


        services.AddIdentity<IdentityUser, IdentityRole>(options =>
        {
            options.Password.RequiredLength = 15;
            options.Password.RequiredUniqueChars = 5;
            options.Password.RequireNonAlphanumeric = false;

            options.SignIn.RequireConfirmedEmail = true;
            options.Tokens.EmailConfirmationTokenProvider = "CustomEmailConfirmation";

            options.Lockout.MaxFailedAccessAttempts = 5;
            options.Lockout.DefaultLockoutTimeSpan = TimeSpan.FromMinutes(15);
        })
        .AddEntityFrameworkStores<Context>()
        .AddDefaultTokenProviders()
        .AddTokenProvider<CustomEmailConfirmationTokenProvider<IdentityUser>>("CustomEmailConfirmation");

        // REGISTER ExtractEMService
        ExtractEMService.ExtractEMRegisterService(services);

        //services.AddMvc().SetCompatibilityVersion(CompatibilityVersion.Version_2_1);
        services.AddMvc(options =>
        {
            var policy = new AuthorizationPolicyBuilder()
            .RequireAuthenticatedUser()
            .Build();
            options.Filters.Add(new AuthorizeFilter(policy));

        }).SetCompatibilityVersion(CompatibilityVersion.Version_2_1);

    // 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.UseDeveloperExceptionPage();
            app.UseDatabaseErrorPage();
        }
        else
        {
            app.UseExceptionHandler("/Error");
            app.UseStatusCodePagesWithReExecute("/Error/{0}");

            //app.UseExceptionHandler("/Home/Error");
            app.UseHsts();
        }

        app.UseHttpsRedirection();
        app.UseStaticFiles();
        app.UseCookiePolicy();

        app.UseAuthentication();

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

Answer 1

没有办法做到这一点，但只需保留生成的类并使用伙伴类进行数据注释：

[MetadataType(typeof(MetaData))]
public partial class Person
{
    public class MetaData
    {
        [Required]
        [Display(Name = "Enter Your Name")]
        public string FirstName;

      
    }
}

https://ryanhayes.net/data-annotations-for-entity-framework-4-entities-as-an-mvc-model/