با استفاده از آموزش دوره  Asp.Net Core 2   ی پروژه ای ایجاد کردم حالا که نوبت به ساخت دیتابیس توسط Migration    میشه  خطای زیر نمایش داده میشود:

 target project 'MyCms.Web' doesn't match your migrations assembly 'MyCms.DataLayer'. Either change your target project or change your migrations assembly.
Change your migrations assembly by using DbContextOptionsBuilder. E.g. options.UseSqlServer(connection, b => b.MigrationsAssembly("MyCms.Web")). By default, the migrations assembly is the assembly containing the DbContext.
Change your target project to the migrations project by using the Package Manager Console's Default project drop-down list, or by executing "dotnet ef" from the directory containing the migrations project.

این قطعه کد مربوط به appsettings.json می باشد:

{
	"Logging": {
		"LogLevel": {
			"Default": "Warning"
		}
	},
	"AllowedHosts": "*",

	"ConnectionStrings": {
		"MyCmsDbContext": "Data Source=.;Initial Catalog =MyCmsCore_DB;Integrated Security=True"
	}
}

و اینم قطعه کد مربوط به Startup می باشد:

	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.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.AddMvc().SetCompatibilityVersion(CompatibilityVersion.Version_2_2);


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

	 
		}

 

		// 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();
			}
			else
			{
				app.UseExceptionHandler("/Home/Error");
				// The default HSTS value is 30 days. You may want to change this for production scenarios, see https://aka.ms/aspnetcore-hsts.
				app.UseHsts();
			}

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

نسخه ای که پروژه باهاش شروع کردم Net Core 2.1 هست...  

لطفا راهنمایی کنید.