[Database Migration] Validation database supports migration job. (#292)

* Extend to validation database

* Delete default constructor of entities

* Update

Author: zhhyu

src/NuGet.Services.Validation/Entities/ValidationEntitiesContext.cs

@@ -1,13 +1,31 @@
 // Copyright (c) .NET Foundation. All rights reserved.
 // Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
 
+using System;
 using System.ComponentModel.DataAnnotations.Schema;
 using System.Data.Common;
 using System.Data.Entity;
+using System.Data.Entity.Infrastructure;
 using System.Data.Entity.Infrastructure.Annotations;
 
 namespace NuGet.Services.Validation
 {
+    /// <summary>
+    /// This ValidationDbContextFactory is provided for running migrations in a flexible way as follows:
+    /// 1. Run migration using DbConnection; (For DatabaseMigrationTools with AAD token)
+    /// 2. Run migration using connection string;
+    /// 3. Run migration using default connection string ("Validation.SqlServer") in a web.config; (For command-line migration with integrated AAD/username+password)
+    /// </summary>
+    public class ValidationDbContextFactory : IDbContextFactory<ValidationEntitiesContext>
+    {
+        public static Func<ValidationEntitiesContext> ValidationEntitiesContextFactory;
+        public ValidationEntitiesContext Create()
+        {
+            var factory = ValidationEntitiesContextFactory;
+            return factory == null ? new ValidationEntitiesContext("Validation.SqlServer") : factory();
+        }
+    }
+
     /// <summary>
     /// The Entity Framework database context for validation entities.
     /// </summary>
@@ -99,10 +117,6 @@ static ValidationEntitiesContext()
         public IDbSet<PackageRevalidation> PackageRevalidations { get; set; }
         public IDbSet<SymbolsServerRequest> SymbolsServerRequests { get; set; }
 
-        public ValidationEntitiesContext() : this("Validation.SqlServer")
-        {
-        }
-
         public ValidationEntitiesContext(string nameOrConnectionString) : base(nameOrConnectionString)
         {
         }

src/NuGet.Services.Validation/Migrations/ValidationMigrationsConfiguration.cs

@@ -5,7 +5,7 @@
 
 namespace NuGet.Services.Validation
 {
-    internal sealed class ValidationMigrationsConfiguration: DbMigrationsConfiguration<ValidationEntitiesContext>
+    public class ValidationMigrationsConfiguration: DbMigrationsConfiguration<ValidationEntitiesContext>
     {
         public ValidationMigrationsConfiguration()
         {