add DB exception filter /6 (#22804)

* add DB exception filter /6

* add DB exception filter /6

* add DB exception filter /6

* add DB exception filter /6

* add DB exception filter /6

aspnetcore/data/ef-rp/intro.md

@@ -364,13 +364,15 @@ See [Use SQLite for development, SQL Server for production](xref:tutorials/razor
 
 The name of the connection string is passed in to the context by calling a method on a [DbContextOptions](/dotnet/api/microsoft.entityframeworkcore.dbcontextoptions) object. For local development, the [ASP.NET Core configuration system](xref:fundamentals/configuration/index) reads the connection string from the *appsettings.json* file.
 
+<a name="dbx"></a>
+
 ### Add the database exception filter
 
-Add <xref:Microsoft.Extensions.DependencyInjection.DatabaseDeveloperPageExceptionFilterServiceExtensions.AddDatabaseDeveloperPageExceptionFilter%2A> to `ConfigureServices` as shown in the following code:
+Add <xref:Microsoft.Extensions.DependencyInjection.DatabaseDeveloperPageExceptionFilterServiceExtensions.AddDatabaseDeveloperPageExceptionFilter%2A> and <xref:Microsoft.AspNetCore.Builder.MigrationsEndPointExtensions.UseMigrationsEndPoint%2A> as shown in the following code:
 
 # [Visual Studio](#tab/visual-studio)
 
-[!code-csharp[Main](intro/samples/cu50/Startup.cs?name=snippet_ConfigureServices&highlight=8)]
+[!code-csharp[Main](intro/samples/cu50/Startup.cs?name=snippet&highlight=8,15-16)]
 
 Add the [Microsoft.AspNetCore.Diagnostics.EntityFrameworkCore](https://www.nuget.org/packages/Microsoft.AspNetCore.Diagnostics.EntityFrameworkCore) NuGet package.
 
@@ -382,13 +384,13 @@ Install-Package Microsoft.AspNetCore.Diagnostics.EntityFrameworkCore
 
 # [Visual Studio Code](#tab/visual-studio-code)
 
-[!code-csharp[Main](intro/samples/cu50/StartupSQLite.cs?name=snippet_ConfigureServices&highlight=8)]
+[!code-csharp[Main](intro/samples/cu50/StartupSQLite.cs?name=snippet_ConfigureServices&highlight=8,16)]
 
 ---
 
 The `Microsoft.AspNetCore.Diagnostics.EntityFrameworkCore` NuGet package provides ASP.NET Core middleware for Entity Framework Core error pages. This middleware helps to detect and diagnose errors with Entity Framework Core migrations.
 
-The `AddDatabaseDeveloperPageExceptionFilter` provides helpful error information in the [development environment](xref:fundamentals/environments).
+The `AddDatabaseDeveloperPageExceptionFilter` provides helpful error information in the [development environment](xref:fundamentals/environments) for EF migrations errors.
 
 ## Create the database
 

aspnetcore/data/ef-rp/intro/samples/cu50/Startup.cs

@@ -17,6 +17,7 @@ namespace ContosoUniversity
 
         public IConfiguration Configuration { get; }
 
+        #region snippet
         #region snippet_ConfigureServices
         public void ConfigureServices(IServiceCollection services)
         {
@@ -34,6 +35,7 @@ namespace ContosoUniversity
             if (env.IsDevelopment())
             {
                 app.UseDeveloperExceptionPage();
+                app.UseMigrationsEndPoint();
             }
             else
             {
@@ -53,5 +55,6 @@ namespace ContosoUniversity
                 endpoints.MapRazorPages();
             });
         }
+        #endregion
     }
 }

aspnetcore/data/ef-rp/intro/samples/cu50/StartupSQLite.cs

@@ -27,13 +27,13 @@ namespace ContosoUniversity
 
             services.AddDatabaseDeveloperPageExceptionFilter();
         }
-        #endregion
 
         public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
         {
             if (env.IsDevelopment())
             {
                 app.UseDeveloperExceptionPage();
+                app.UseMigrationsEndPoint();
             }
             else
             {
@@ -53,5 +53,6 @@ namespace ContosoUniversity
                 endpoints.MapRazorPages();
             });
         }
+        #endregion
     }
 }