Phase 2: Data Layer Migration from Entity Framework 6.1.3 to Entity Framework Core

- Update DataLayer.Core to target net8.0 with EF Core 8.0 packages
- Migrate entity classes (Blog, Post, Tag) with validation logic preserved
- Create SampleWebAppDbCore DbContext with change tracking and model configuration
- Add TrackUpdate helper class for LastUpdated tracking
- Create DataLayerCoreInitialise for database initialization
- Add LoadDbDataFromXml helper for seeding data from XML files
- Copy XML data files (BlogsContentSimple.xml, BlogsContextMedium.xml)
- Update ServiceLayer.Core to target net8.0 for compatibility
- Add comprehensive unit tests for DataLayer.Core (15 tests)
- Configure Tag Slug uniqueness constraint in OnModelCreating
- Preserve all entity relationships (Blog-Post, Post-Tag many-to-many)

Co-Authored-By: Abhay Aggarwal <abhay.aggarwal@codeium.com>

Author: devin-ai-integration[bot]

DataLayer.Core/Class1.cs

@@ -0,0 +1,54 @@
+#region licence
+// The MIT License (MIT)
+// 
+// Filename: Blog.cs
+// Date Created: 2014/05/20
+// 
+// Copyright (c) 2014 Jon Smith (www.selectiveanalytics.com & www.thereformedprogrammer.net)
+// 
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+// 
+// The above copyright notice and this permission notice shall be included in all
+// copies or substantial portions of the Software.
+// 
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+// SOFTWARE.
+#endregion
+using System.Collections.Generic;
+using System.ComponentModel.DataAnnotations;
+
+namespace DataLayer.Core.DataClasses.Concrete
+{
+    public class Blog
+    {
+        public int BlogId { get; set; }
+
+        [MinLength(2)]
+        [MaxLength(64)]
+        [Required]
+        public string Name { get; set; }
+
+        [MaxLength(256)]
+        [Required]
+        [EmailAddress]
+        public string EmailAddress { get; set; }
+
+        public ICollection<Post> Posts { get; set; }
+
+        public override string ToString()
+        {
+            return string.Format("BlogId: {0}, Name: {1}, EmailAddress: {2}, NumPosts: {3}", 
+                BlogId, Name, EmailAddress, Posts == null ? "null" : Posts.Count.ToString());
+        }
+    } 
+}

DataLayer.Core/DataClasses/Concrete/Blog.cs

@@ -0,0 +1,45 @@
+#region licence
+// The MIT License (MIT)
+// 
+// Filename: TrackUpdate.cs
+// Date Created: 2014/05/20
+// 
+// Copyright (c) 2014 Jon Smith (www.selectiveanalytics.com & www.thereformedprogrammer.net)
+// 
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+// 
+// The above copyright notice and this permission notice shall be included in all
+// copies or substantial portions of the Software.
+// 
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+// SOFTWARE.
+#endregion
+using System;
+
+namespace DataLayer.Core.DataClasses.Concrete.Helpers
+{
+    public abstract class TrackUpdate
+    {
+        public DateTime LastUpdated { get; protected set; }
+
+        internal void UpdateTrackingInfo()
+        {
+            LastUpdated = DateTime.UtcNow;
+        }
+
+        protected TrackUpdate()
+        {
+            UpdateTrackingInfo();
+        }
+    }
+}

DataLayer.Core/DataClasses/Concrete/Helpers/TrackUpdate.cs

@@ -0,0 +1,76 @@
+#region licence
+// The MIT License (MIT)
+// 
+// Filename: Post.cs
+// Date Created: 2014/05/20
+// 
+// Copyright (c) 2014 Jon Smith (www.selectiveanalytics.com & www.thereformedprogrammer.net)
+// 
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+// 
+// The above copyright notice and this permission notice shall be included in all
+// copies or substantial portions of the Software.
+// 
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+// SOFTWARE.
+#endregion
+using System.Collections.Generic;
+using System.ComponentModel.DataAnnotations;
+using System.Linq;
+using DataLayer.Core.DataClasses.Concrete.Helpers;
+
+namespace DataLayer.Core.DataClasses.Concrete
+{
+    public class Post : TrackUpdate, IValidatableObject
+    {
+        public int PostId { get; set; }
+
+        [MinLength(2), MaxLength(128)]
+        [Required]
+        public string Title { get; set; }
+
+        [Required]
+        public string Content { get; set; }
+
+        public int BlogId { get; set; }
+        public virtual Blog Blogger { get; set; }
+
+        public ICollection<Tag> Tags { get; set; }
+
+        public override string ToString()
+        {
+            return string.Format("PostId: {0}, Title: {1}, BlogId: {2}, Blogger: {3}, AllocatedTags: {4}", 
+                PostId, Title, BlogId, Blogger == null ? "null" : Blogger.Name, Tags == null ? "null" : Tags.Count().ToString());
+        }
+
+        public IEnumerable<ValidationResult> Validate(ValidationContext validationContext)
+        {
+            if (Tags != null && !Tags.Any())
+                yield return new ValidationResult("The post must have at least one Tag.", new[] { "AllocatedTags" });
+
+            if (Title.Contains("!"))
+                yield return new ValidationResult("Sorry, but you can't get too excited and include a ! in the title.", new[] { "Title" });
+            if (Title.EndsWith("?"))
+                yield return new ValidationResult("Sorry, but you can't ask a question, i.e. the title can't end with '?'.", new[] { "Title" });
+
+            if (Content.Contains(" sheep."))
+                yield return new ValidationResult("Sorry. Not allowed to end a sentance with 'sheep'.");
+            if (Content.Contains(" lamb."))
+                yield return new ValidationResult("Sorry. Not allowed to end a sentance with 'lamb'.");
+            if (Content.Contains(" cow."))
+                yield return new ValidationResult("Sorry. Not allowed to end a sentance with 'cow'.");
+            if (Content.Contains(" calf."))
+                yield return new ValidationResult("Sorry. Not allowed to end a sentance with 'calf'.");
+        }
+    }
+}

DataLayer.Core/DataClasses/Concrete/Post.cs

@@ -0,0 +1,52 @@
+#region licence
+// The MIT License (MIT)
+// 
+// Filename: Tag.cs
+// Date Created: 2014/05/20
+// 
+// Copyright (c) 2014 Jon Smith (www.selectiveanalytics.com & www.thereformedprogrammer.net)
+// 
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+// 
+// The above copyright notice and this permission notice shall be included in all
+// copies or substantial portions of the Software.
+// 
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+// SOFTWARE.
+#endregion
+using System.Collections.Generic;
+using System.ComponentModel.DataAnnotations;
+
+namespace DataLayer.Core.DataClasses.Concrete
+{
+    public class Tag
+    {
+        public int TagId { get; set; }
+
+        [MaxLength(64)]
+        [Required]
+        [RegularExpression(@"\w*", ErrorMessage = "The slug must not contain spaces or non-alphanumeric characters.")]
+        public string Slug { get; set; }
+
+        [MaxLength(128)]
+        [Required]
+        public string Name { get; set; }
+
+        public ICollection<Post> Posts { get; set; }
+
+        public override string ToString()
+        {
+            return string.Format("TagId: {0}, Name: {1}, Slug: {2}", TagId, Name, Slug);
+        }
+    }
+}

DataLayer.Core/DataClasses/Concrete/Tag.cs

@@ -0,0 +1,125 @@
+#region licence
+// The MIT License (MIT)
+// 
+// Filename: SampleWebAppDbCore.cs
+// Date Created: 2014/05/20
+// 
+// Copyright (c) 2014 Jon Smith (www.selectiveanalytics.com & www.thereformedprogrammer.net)
+// 
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+// 
+// The above copyright notice and this permission notice shall be included in all
+// copies or substantial portions of the Software.
+// 
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+// SOFTWARE.
+#endregion
+using System;
+using System.Linq;
+using System.Threading;
+using System.Threading.Tasks;
+using DataLayer.Core.DataClasses.Concrete;
+using DataLayer.Core.DataClasses.Concrete.Helpers;
+using Microsoft.EntityFrameworkCore;
+
+namespace DataLayer.Core.DataClasses
+{
+    public class SampleWebAppDbCore : DbContext
+    {
+        public const string NameOfConnectionString = "SampleWebAppDb";
+
+        private static readonly string DefaultConnectionString = 
+            @"Data Source=(localdb)\mssqllocaldb;Initial Catalog=SampleWebAppDb;MultipleActiveResultSets=True;Integrated Security=SSPI;Trusted_Connection=True";
+
+        private readonly string _connectionString;
+
+        public DbSet<Blog> Blogs { get; set; }
+        public DbSet<Post> Posts { get; set; }
+        public DbSet<Tag> Tags { get; set; }
+
+        public SampleWebAppDbCore() : base()
+        {
+            _connectionString = DefaultConnectionString;
+        }
+
+        public SampleWebAppDbCore(DbContextOptions<SampleWebAppDbCore> options) : base(options)
+        {
+        }
+
+        public SampleWebAppDbCore(string connectionString) : base()
+        {
+            _connectionString = connectionString;
+        }
+
+        protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
+        {
+            if (!optionsBuilder.IsConfigured)
+            {
+                optionsBuilder.UseSqlServer(_connectionString ?? DefaultConnectionString);
+            }
+        }
+
+        protected override void OnModelCreating(ModelBuilder modelBuilder)
+        {
+            base.OnModelCreating(modelBuilder);
+
+            modelBuilder.Entity<Tag>()
+                .HasIndex(t => t.Slug)
+                .IsUnique();
+
+            modelBuilder.Entity<Post>()
+                .HasOne(p => p.Blogger)
+                .WithMany(b => b.Posts)
+                .HasForeignKey(p => p.BlogId);
+
+            modelBuilder.Entity<Post>()
+                .HasMany(p => p.Tags)
+                .WithMany(t => t.Posts);
+        }
+
+        public override int SaveChanges()
+        {
+            HandleChangeTracking();
+            return base.SaveChanges();
+        }
+
+        public override int SaveChanges(bool acceptAllChangesOnSuccess)
+        {
+            HandleChangeTracking();
+            return base.SaveChanges(acceptAllChangesOnSuccess);
+        }
+
+        public override Task<int> SaveChangesAsync(CancellationToken cancellationToken = default)
+        {
+            HandleChangeTracking();
+            return base.SaveChangesAsync(cancellationToken);
+        }
+
+        public override Task<int> SaveChangesAsync(bool acceptAllChangesOnSuccess, CancellationToken cancellationToken = default)
+        {
+            HandleChangeTracking();
+            return base.SaveChangesAsync(acceptAllChangesOnSuccess, cancellationToken);
+        }
+
+        private void HandleChangeTracking()
+        {
+            foreach (var entity in ChangeTracker.Entries()
+                                                .Where(e => e.State == EntityState.Added || e.State == EntityState.Modified))
+            {
+                var trackUpdateClass = entity.Entity as TrackUpdate;
+                if (trackUpdateClass == null) continue;
+                trackUpdateClass.UpdateTrackingInfo();
+            }
+        }
+    }
+}

DataLayer.Core/DataClasses/SampleWebAppDbCore.cs

@@ -1,7 +1,24 @@
-<Project Sdk="Microsoft.NET.Sdk">
+<Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <TargetFramework>netstandard2.0</TargetFramework>
+    <TargetFramework>net8.0</TargetFramework>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <Nullable>enable</Nullable>
   </PropertyGroup>
 
+  <ItemGroup>
+    <PackageReference Include="Microsoft.EntityFrameworkCore" Version="8.0.0" />
+    <PackageReference Include="Microsoft.EntityFrameworkCore.SqlServer" Version="8.0.0" />
+    <PackageReference Include="Microsoft.EntityFrameworkCore.Tools" Version="8.0.0">
+      <PrivateAssets>all</PrivateAssets>
+      <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
+    </PackageReference>
+    <PackageReference Include="Microsoft.Extensions.Configuration.Abstractions" Version="8.0.0" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <EmbeddedResource Include="Startup\Internal\BlogsContentSimple.xml" />
+    <EmbeddedResource Include="Startup\Internal\BlogsContextMedium.xml" />
+  </ItemGroup>
+
 </Project>