diff --git a/src/DbContextLib/HeartTrackContext.cs b/src/DbContextLib/HeartTrackContext.cs
index 919007b..5dbb584 100644
--- a/src/DbContextLib/HeartTrackContext.cs
+++ b/src/DbContextLib/HeartTrackContext.cs
@@ -8,7 +8,7 @@
 
 using Entities;
 using Microsoft.EntityFrameworkCore;
-using Microsoft.EntityFrameworkCore.Migrations.Operations;
+
 
 namespace DbContextLib
 {
diff --git a/src/Entities/FriendshipEntity.cs b/src/Entities/FriendshipEntity.cs
index fb7446f..6fadb15 100644
--- a/src/Entities/FriendshipEntity.cs
+++ b/src/Entities/FriendshipEntity.cs
@@ -6,9 +6,9 @@ public class FriendshipEntity
 {
     [ForeignKey("FollowingId")]
     public int FollowingId { get; set; }
-    public AthleteEntity Following { get; set; }
+    public AthleteEntity Following { get; set; } = null!;
     [ForeignKey("FollowerId")]
     public int FollowerId { get; set; }
-    public AthleteEntity Follower { get; set; }
+    public AthleteEntity Follower { get; set; } = null!;
     public DateTime StartDate { get; set; }
 }
\ No newline at end of file
diff --git a/src/Entities/Picture.cs b/src/Entities/Picture.cs
index 53ab376..61ebedb 100644
--- a/src/Entities/Picture.cs
+++ b/src/Entities/Picture.cs
@@ -2,10 +2,8 @@ using System.ComponentModel.DataAnnotations;
 
 public class Picture
 {
-
         [Key]
         public Guid Id { get; set; }
         [Required]
-        public byte[] Bytes { get; set; }  
-
+        public byte[] Bytes { get; set; } = null!;
 }
\ No newline at end of file
diff --git a/src/Model2Entities/ActivityRepository.cs b/src/Model2Entities/ActivityRepository.cs
index 7d1b1a4..f879b17 100644
--- a/src/Model2Entities/ActivityRepository.cs
+++ b/src/Model2Entities/ActivityRepository.cs
@@ -15,6 +15,21 @@ public partial class DbDataManager
 
         public async Task<IEnumerable<Activity>> GetItems(int index, int count, Enum? orderingProperty = null, bool descending = false)
         {
+            // public class MyLogger
+            // {
+            //     public void Log(string component, string message)
+            //     {
+            //         Console.WriteLine("Component: {0} Message: {1} ", component, message);
+            //     }
+            // }
+            // ? Utilisation du logger !!!
+            //! using (var context = new LibraryContext()) 
+            //! {
+                // var logger = new MyLogger();
+                // context.Database.Log = s => logger.Log("EFApp", s);
+            //!     // log la connexion à la base de donnée
+            //!     context.Database.Log = Console.Write;
+            //! }
             throw new NotImplementedException();
         }
 
diff --git a/src/Model2Entities/Extension.cs b/src/Model2Entities/Extension.cs
new file mode 100644
index 0000000..d404f58
--- /dev/null
+++ b/src/Model2Entities/Extension.cs
@@ -0,0 +1,27 @@
+// using System;
+// using Entities;
+// using Models;
+
+// namespace Model2Entities
+// {
+// 	public static class Extension<Tentity>
+// 	{
+// 		public static TEntity ToEntity(this Book model)
+// 			=> new BookEntity
+// 			{
+// 				Id = model.Id,
+// 				Title = model.Title,
+// 				Author = model.Author,
+// 				Isbn = model.Isbn
+// 			};
+
+//         public static IEnumerable<TEntity> ToEntities(this IEnumerable<Book> models)
+//             => models.Select(m => m.ToEntity());
+
+//         public static Book ToModel(this TEntity myBookEntity)
+// 			=> new Book(myBookEntity.Id, myBookEntity.Title, myBookEntity.Author, myBookEntity.Isbn);
+		
+// 		public static IEnumerable<Book> ToModels(this IEnumerable<BookEntity> booksEntities)
+// 			=> booksEntities.Select(e => e.ToModel());
+//     }
+// }
\ No newline at end of file
diff --git a/src/Tests/ConsoleTestRelationships/Program.cs b/src/Tests/ConsoleTestRelationships/Program.cs
index 6589076..36dad0c 100644
--- a/src/Tests/ConsoleTestRelationships/Program.cs
+++ b/src/Tests/ConsoleTestRelationships/Program.cs
@@ -1,5 +1,6 @@
 
 using DbContextLib;
+using Entities;
 using Microsoft.Data.Sqlite;
 using Microsoft.EntityFrameworkCore;
 using Microsoft.Extensions.Options;
@@ -274,41 +275,6 @@ class Program
             Console.WriteLine($"");
             
             Console.WriteLine($"\t\t{athlete.Followers.Aggregate("", (seed, kvp) => $"{seed} [{kvp.FollowerId} ; {kvp.FollowingId} ; {kvp.StartDate.ToString("dd/MM/yyyy hh:mm:ss")}]")}");
-
-            // Console.WriteLine("\t\tFollowers :");
-            // Console.WriteLine("\t\t---------------------------------");
-
-            // foreach (var followers in athlete.Followers)
-            // {
-            //     Console.WriteLine($"\t\t\t{followers.IdAthlete} - {followers.FirstName}, {followers.LastName}, {followers.DateOfBirth}, {followers.Sexe}, {followers.Weight}, {followers.IsCoach}");
-            // }
-
-            // Console.WriteLine("\t\tFollowings :");
-            // Console.WriteLine("\t\t---------------------------------");
-
-            // foreach (var following in athlete.Followings)
-            // {
-            //     // Console.WriteLine($"\t\t{following.Followings.Aggregate("", (seed, kvp) => $"{seed} [{kvp.ArtistEntityId} ; {kvp.CreatedOn.ToString("dd/MM/yyyy hh:mm:ss")}]")}");
-            //     Console.WriteLine($"\t\t\t{following.IdAthlete} - {following.FirstName}, {following.LastName}, {following.DateOfBirth}, {following.Sexe}, {following.Weight}, {following.IsCoach}");
-            // }
-
-            // using (MyDbContext db = new MyDbContext())
-            // {
-            //     WriteLine("Content of database (albums) : ");
-            //     foreach (var al in db.Albums.Include(a => a.Artists))
-            //     {
-            //         WriteLine($"\t{al}");
-            //         WriteLine($"\t\t{al.AlbumArtists.Aggregate("", (seed, kvp) => $"{seed} [{kvp.ArtistEntityId} ; {kvp.CreatedOn.ToString("dd/MM/yyyy hh:mm:ss")}]")}");
-            //     }
-
-            //     WriteLine("Content of database (artists) : ");
-            //     foreach (var ar in db.Artists)
-            //     {
-            //         WriteLine($"\t{ar}");
-            //         WriteLine($"\t\t{ar.ArtistAlbums.Aggregate("", (seed, kvp) => $"{seed} [{kvp.AlbumEntityId} ; {kvp.CreatedOn.ToString("dd/MM/yyyy hh:mm:ss")}]")}");
-            //     }
-            // }
         }
     }
-
 }
\ No newline at end of file
diff --git a/src/Tests/ConsoleTestRelationships/uca.HeartTrack.db b/src/Tests/ConsoleTestRelationships/uca.HeartTrack.db
new file mode 100644
index 0000000..bde4d91
Binary files /dev/null and b/src/Tests/ConsoleTestRelationships/uca.HeartTrack.db differ