diff --git a/WebApi/DTOs/AdministratorDto.cs b/WebApi/DTOs/AdministratorDto.cs
index 6c6c1de..a2a4505 100644
--- a/WebApi/DTOs/AdministratorDto.cs
+++ b/WebApi/DTOs/AdministratorDto.cs
@@ -16,7 +16,7 @@ namespace DTOs
     /// </summary>
     public class AdministratorDto
     {
-        public uint Id { get; set; }
+        public int Id { get; set; }
         public string Username { get; set; } = null!;
         public string HashedPassword { get; set; } = null!;
     }
diff --git a/WebApi/DTOs/AnswerDto.cs b/WebApi/DTOs/AnswerDto.cs
index 347b2d5..fb75004 100644
--- a/WebApi/DTOs/AnswerDto.cs
+++ b/WebApi/DTOs/AnswerDto.cs
@@ -13,8 +13,8 @@ namespace DTOs
     /// </summary>
     public class AnswerDto
     {
-        public uint Id { get; set; }
+        public int Id { get; set; }
         public string Content { get; set; } = null!;
-        public uint? IdQuestion { get; set; }
+        public int? IdQuestion { get; set; }
     }
 }
diff --git a/WebApi/DTOs/ChapterDto.cs b/WebApi/DTOs/ChapterDto.cs
index 739f5eb..8c5fa02 100644
--- a/WebApi/DTOs/ChapterDto.cs
+++ b/WebApi/DTOs/ChapterDto.cs
@@ -15,7 +15,7 @@ namespace DTOs
     /// </summary>
     public class ChapterDto
     {
-        public uint Id { get; set; }
+        public int Id { get; set; }
         public string Name { get; set; } = null!;
     }
 }
diff --git a/WebApi/DTOs/LobbyDto.cs b/WebApi/DTOs/LobbyDto.cs
index abec694..015b224 100644
--- a/WebApi/DTOs/LobbyDto.cs
+++ b/WebApi/DTOs/LobbyDto.cs
@@ -18,10 +18,10 @@ namespace DTOs
     /// </summary>
     public class LobbyDto
     {
-        public uint Id { get; set; }
+        public int Id { get; set; }
         public string Name { get; set; } = null!;
         public string Password { get; set; } = null!;
-        public uint NbPlayers { get; set; }
-        public uint? IdCreator { get; set; }
+        public int NbPlayers { get; set; }
+        public int? IdCreator { get; set; }
     }
 }
diff --git a/WebApi/DTOs/PlayerDto.cs b/WebApi/DTOs/PlayerDto.cs
index 30e86f6..6b4a26b 100644
--- a/WebApi/DTOs/PlayerDto.cs
+++ b/WebApi/DTOs/PlayerDto.cs
@@ -16,7 +16,7 @@ namespace DTOs
     /// </summary>
     public class PlayerDto
     {
-        public uint Id { get; set; }
+        public int Id { get; set; }
         public string Nickname { get; set; } = null!;
         public string HashedPassword { get; set; } = null!;
     }
diff --git a/WebApi/DTOs/QuestionDto.cs b/WebApi/DTOs/QuestionDto.cs
index 488616d..5a5e33f 100644
--- a/WebApi/DTOs/QuestionDto.cs
+++ b/WebApi/DTOs/QuestionDto.cs
@@ -20,11 +20,11 @@ namespace DTOs
     /// </summary>
     public class QuestionDto
     {
-        public uint Id { get; set; }
+        public int Id { get; set; }
         public string Content { get; set; } = null!;
         public byte Difficulty { get; set; }
-        public uint NbFalls { get; set; }
-        public uint IdChapter { get; set; }
-        public uint? IdAnswerGood { get; set; }
+        public int NbFalls { get; set; }
+        public int IdChapter { get; set; }
+        public int? IdAnswerGood { get; set; }
     }
 }
diff --git a/WebApi/Entities/AdministratorEntity.cs b/WebApi/Entities/AdministratorEntity.cs
index c9b2536..969c6fa 100644
--- a/WebApi/Entities/AdministratorEntity.cs
+++ b/WebApi/Entities/AdministratorEntity.cs
@@ -15,7 +15,7 @@ namespace Entities
     {
         [Key]
         [DatabaseGenerated(DatabaseGeneratedOption.Identity)]
-        public uint Id { get; set; }
+        public int Id { get; set; }
         [Required]
         public string Username { get; set; } = null!;
         [Required]
diff --git a/WebApi/Entities/AnswerEntity.cs b/WebApi/Entities/AnswerEntity.cs
index deb6e9b..a8f92e8 100644
--- a/WebApi/Entities/AnswerEntity.cs
+++ b/WebApi/Entities/AnswerEntity.cs
@@ -16,12 +16,12 @@ namespace Entities
     {
         [Key]
         [DatabaseGenerated(DatabaseGeneratedOption.Identity)]
-        public uint Id { get; set; }
+        public int Id { get; set; }
         [Required]
         public string Content { get; set; } = null!;
 
         [ForeignKey(nameof(Question))]
-        public uint? IdQuestion { get; set; }
+        public int? IdQuestion { get; set; }
 
         public QuestionEntity? Question { get; set; }
     }
diff --git a/WebApi/Entities/ChapterEntity.cs b/WebApi/Entities/ChapterEntity.cs
index 379d1c1..6d78723 100644
--- a/WebApi/Entities/ChapterEntity.cs
+++ b/WebApi/Entities/ChapterEntity.cs
@@ -14,7 +14,7 @@ namespace Entities
     {
         [Key]
         [DatabaseGenerated(DatabaseGeneratedOption.Identity)]
-        public uint Id { get; set; }
+        public int Id { get; set; }
         [Required]
         public string Name { get; set; } = null!;
     }
diff --git a/WebApi/Entities/LobbyEntity.cs b/WebApi/Entities/LobbyEntity.cs
index 9ddcf5b..3fbd264 100644
--- a/WebApi/Entities/LobbyEntity.cs
+++ b/WebApi/Entities/LobbyEntity.cs
@@ -18,14 +18,14 @@ namespace Entities
     {
         [Key]
         [DatabaseGenerated(DatabaseGeneratedOption.Identity)]
-        public uint Id { get; set; }
+        public int Id { get; set; }
         [Required]
         public string Name { get; set; } = null!;
         public string Password { get; set; } = null!;
-        public uint NbPlayers { get; set; }
+        public int NbPlayers { get; set; }
 
         [ForeignKey(nameof(Creator))]
-        public uint? IdCreator { get; set; }
+        public int? IdCreator { get; set; }
 
         public PlayerEntity? Creator { get; set; }
     }
diff --git a/WebApi/Entities/LobbyEntityPlayerEntity.cs b/WebApi/Entities/LobbyEntityPlayerEntity.cs
index 271d093..1150c67 100644
--- a/WebApi/Entities/LobbyEntityPlayerEntity.cs
+++ b/WebApi/Entities/LobbyEntityPlayerEntity.cs
@@ -14,14 +14,14 @@ namespace Entities
     public class LobbyEntityPlayerEntity
     {
         [ForeignKey(nameof(Lobby))]
-        public uint IdLobby { get; set; }
+        public int IdLobby { get; set; }
 
         [ForeignKey(nameof(Player))]
-        public uint IdPlayer { get; set; }
+        public int IdPlayer { get; set; }
 
         public LobbyEntity Lobby { get; set; } = null!;
         public PlayerEntity Player { get; set; } = null!;
 
-        public uint MaxScore { get; set; }
+        public int MaxScore { get; set; }
     }
 }
diff --git a/WebApi/Entities/PlayerEntity.cs b/WebApi/Entities/PlayerEntity.cs
index 764bc6c..5dda62c 100644
--- a/WebApi/Entities/PlayerEntity.cs
+++ b/WebApi/Entities/PlayerEntity.cs
@@ -15,7 +15,7 @@ namespace Entities
     {
         [Key]
         [DatabaseGenerated(DatabaseGeneratedOption.Identity)]
-        public uint Id { get; set; }
+        public int Id { get; set; }
         [Required]
         public string Nickname { get; set; } = null!;
         [Required]
diff --git a/WebApi/Entities/PlayerEntityChapterEntity.cs b/WebApi/Entities/PlayerEntityChapterEntity.cs
index 25a23ac..9f73ad0 100644
--- a/WebApi/Entities/PlayerEntityChapterEntity.cs
+++ b/WebApi/Entities/PlayerEntityChapterEntity.cs
@@ -21,16 +21,16 @@ namespace Entities
     {
         [ForeignKey(nameof(Chapter))]
         [DatabaseGenerated(DatabaseGeneratedOption.None)]
-        public uint IdChapter { get; set; }
+        public int IdChapter { get; set; }
 
         [ForeignKey(nameof(Player))]
         [DatabaseGenerated(DatabaseGeneratedOption.None)]
-        public uint IdPlayer { get; set; }
+        public int IdPlayer { get; set; }
 
         public ChapterEntity Chapter { get; set; } = null!;
         public PlayerEntity Player { get; set; } = null!;
 
 
-        public uint MaxScore { get; set; }
+        public int MaxScore { get; set; }
     }
 }
diff --git a/WebApi/Entities/QuestionEntity.cs b/WebApi/Entities/QuestionEntity.cs
index f2ef4d3..faf3937 100644
--- a/WebApi/Entities/QuestionEntity.cs
+++ b/WebApi/Entities/QuestionEntity.cs
@@ -25,18 +25,18 @@ namespace Entities
     {
         [Key]
         [DatabaseGenerated(DatabaseGeneratedOption.Identity)]
-        public uint Id { get; set; }
+        public int Id { get; set; }
         [Required]
         public string Content { get; set; } = null!;
         [AllowedValues(1, 2, 3)]
         public byte Difficulty { get; set; }
-        public uint NbFalls { get; set; }
+        public int NbFalls { get; set; }
 
         [ForeignKey(nameof(Chapter))]
-        public uint IdChapter { get; set; }
+        public int IdChapter { get; set; }
 
         [ForeignKey(nameof(AnswerGood))]
-        public uint? IdAnswerGood { get; set; }
+        public int? IdAnswerGood { get; set; }
 
         public ChapterEntity? Chapter { get; set; }
 
diff --git a/WebApi/Model/Administrator.cs b/WebApi/Model/Administrator.cs
index d7e80dd..b845d9d 100644
--- a/WebApi/Model/Administrator.cs
+++ b/WebApi/Model/Administrator.cs
@@ -16,11 +16,11 @@ namespace Model
     /// </summary>
     public class Administrator
     {
-        private uint id;
+        private int id;
         private string? username;
         private string? hashedPassword;
         //      getters and setters for attributes
-        public uint Id
+        public int Id
         {
             get => id;
             private set { id = value; }
@@ -42,7 +42,7 @@ namespace Model
         /// <param name="username">the username of the administrator</param>
         /// <param name="hashedPassword">the hash of the password of the administrator</param>
         /// <param name="id">the id in the database</param>
-        public Administrator(string username, string hashedPassword, uint id = 0)
+        public Administrator(string username, string hashedPassword, int id = 0)
         {
             this.Username = username;
             this.HashedPassword = hashedPassword;
diff --git a/WebApi/Model/Answer.cs b/WebApi/Model/Answer.cs
index e3705b8..49c0c1c 100644
--- a/WebApi/Model/Answer.cs
+++ b/WebApi/Model/Answer.cs
@@ -12,12 +12,12 @@ namespace Model
     /// </summary>
     public class Answer
     {
-        private uint id;
+        private int id;
         private string? content;
-        private uint? idQuestion;
+        private int? idQuestion;
 
         //      getters and setters for attributes
-        public uint Id
+        public int Id
         {
             get => id;
             private set { id = value; }
@@ -27,7 +27,7 @@ namespace Model
             get => content == null ? "" : content;
             set { content = value == "" ? null : value; }
         }
-        public uint? IdQuestion
+        public int? IdQuestion
         {
             get => idQuestion; // null = no idQuestion
             set { idQuestion = value; }
@@ -39,7 +39,7 @@ namespace Model
         /// <param name="content">the content of the answer</param>
         /// <param name="idQuestion">the id of the question which it answer to</param>
         /// <param name="id">the id in the database</param>
-        public Answer(string content, uint? idQuestion = null, uint id = 0)
+        public Answer(string content, int? idQuestion = null, int id = 0)
         {
             Content = content;
             IdQuestion = idQuestion;
diff --git a/WebApi/Model/Chapter.cs b/WebApi/Model/Chapter.cs
index 3c1662f..4ec95a1 100644
--- a/WebApi/Model/Chapter.cs
+++ b/WebApi/Model/Chapter.cs
@@ -15,10 +15,10 @@ namespace Model
     /// </summary>
     public class Chapter
     {
-        uint id;
+        int id;
         string? name;
         //      getters and setters for attributs
-        public uint Id
+        public int Id
         {
             get => id;
             private set { id = value; }
@@ -34,7 +34,7 @@ namespace Model
         /// </summary>
         /// <param name="name">name of the chapter</param>
         /// <param name="id">id in the database</param>
-        public Chapter(string name, uint id = 0)
+        public Chapter(string name, int id = 0)
         {
             Name = name;
             Id = id;
diff --git a/WebApi/Model/Lobby.cs b/WebApi/Model/Lobby.cs
index b399a18..3fde81a 100644
--- a/WebApi/Model/Lobby.cs
+++ b/WebApi/Model/Lobby.cs
@@ -18,13 +18,13 @@ namespace Model
     /// </summary>
     public class Lobby
     {
-        private uint id;
+        private int id;
         private string? name;
         private string? password;
-        private uint nbPlayers;
-        private uint? idCreator;
+        private int nbPlayers;
+        private int? idCreator;
         //      getters and setters of attributes
-        public uint Id
+        public int Id
         {
             get => id;
             private set { id = value; }
@@ -39,12 +39,12 @@ namespace Model
             get => password == null ? "" : password;
             private set { password = value == "" ? null : value; }
         }
-        public uint NbPlayers
+        public int NbPlayers
         {
             get => nbPlayers;
             set { nbPlayers = value; }
         }
-        public uint? IdCreator
+        public int? IdCreator
         {
             get => idCreator;
             private set { idCreator = value; }
@@ -58,7 +58,7 @@ namespace Model
         /// <param name="password">the password require to access to the lobby</param>
         /// <param name="nbPlayers">the number of players in the lobby</param>
         /// <param name="id">the id of the lobby</param>
-        public Lobby(string name, uint? idCreator, string password = "", uint nbPlayers = 0, uint id = 0)
+        public Lobby(string name, int? idCreator, string password = "", int nbPlayers = 0, int id = 0)
         {
             Name = name;
             IdCreator = idCreator;
diff --git a/WebApi/Model/Player.cs b/WebApi/Model/Player.cs
index 92382f5..033e301 100644
--- a/WebApi/Model/Player.cs
+++ b/WebApi/Model/Player.cs
@@ -16,12 +16,12 @@ namespace Model
     /// </summary>
     public class Player
     {
-        private uint id;
+        private int id;
         private string? nickname;
         private string? hashedPassword;
 
         //      getters and setters for attributes
-        public uint Id
+        public int Id
         {
             get => id;
             private set { id = value; }
@@ -43,7 +43,7 @@ namespace Model
         /// <param name="nickname">nickname of the player</param>
         /// <param name="hashedPassword">hash of the password of the player</param>
         /// <param name="id">id of the player</param>
-        public Player(string nickname, string hashedPassword = "", uint id = 0)
+        public Player(string nickname, string hashedPassword = "", int id = 0)
         {
             Nickname = nickname;
             HashedPassword = hashedPassword;
diff --git a/WebApi/Model/Question.cs b/WebApi/Model/Question.cs
index c84c4c6..7bf667a 100644
--- a/WebApi/Model/Question.cs
+++ b/WebApi/Model/Question.cs
@@ -20,14 +20,14 @@ namespace Model
     /// </summary>
     public class Question
     {
-        private uint id;
+        private int id;
         private string? content;
         private byte difficulty;
-        private uint nbFalls;
-        private uint idChapter;
-        private uint? idAnswerGood;
+        private int nbFalls;
+        private int idChapter;
+        private int? idAnswerGood;
 
-        public uint Id
+        public int Id
         {
             get => id;
             private set { id = value; }
@@ -42,23 +42,23 @@ namespace Model
             get => difficulty;
             set { difficulty = value; }
         }
-        public uint NbFalls
+        public int NbFalls
         {
             get => nbFalls;
             set { nbFalls = value; }
         }
-        public uint IdChapter
+        public int IdChapter
         {
             get => idChapter;
             private set { idChapter = value; }
         }
-        public uint? IdAnswerGood
+        public int? IdAnswerGood
         {
             get => idAnswerGood;
             set { idAnswerGood = value; }
         }
 
-        public Question(string content, uint idChapter, uint id = 0, uint? idAnswerGood = null)
+        public Question(string content, int idChapter, int id = 0, int? idAnswerGood = null)
         {
             Id = id;
             Content = content;