add: change userid to guid and small fixes

Backend/Backend.csproj

@@ -14,7 +14,7 @@
   </ItemGroup>
 
   <ItemGroup>
-    <ProjectReference Include="..\Database\Database.csproj" />
+    <ProjectReference Include="..\DbConnect\DbConnect.csproj" />
   </ItemGroup>
 
 </Project>

Backend/Features/Auth/AuthService.cs

@@ -1,4 +1,5 @@
-using Database.Models;
+using DbConnect.Data;
+using DbConnect.Entities;
 using Microsoft.EntityFrameworkCore;
 using Microsoft.IdentityModel.Tokens;
 using System.IdentityModel.Tokens.Jwt;
@@ -18,12 +19,12 @@ namespace Backend.Features.Auth
 
     public class AuthService : IAuthService
     {
-        private readonly LibraryManagementContext _context;
+        private readonly AppDbContext _context;
         private readonly IConfiguration _configuration;
         private readonly ISubscriptionService _subscriptionService;
         private readonly ILoyaltyService _loyaltyService;
 
-        public AuthService(LibraryManagementContext context, IConfiguration configuration, ISubscriptionService subscriptionService, ILoyaltyService loyaltyService)
+        public AuthService(AppDbContext context, IConfiguration configuration, ISubscriptionService subscriptionService, ILoyaltyService loyaltyService)
         {
             _context = context;
             _configuration = configuration;

Backend/Features/Books/BookService.cs

@@ -1,4 +1,5 @@
-using Database.Models;
+using DbConnect.Data;
+using DbConnect.Entities;
 using Microsoft.EntityFrameworkCore;
 
 namespace Backend.Features.Books
@@ -14,9 +15,9 @@ namespace Backend.Features.Books
 
     public class BookService : IBookService
     {
-        private readonly LibraryManagementContext _context;
+        private readonly AppDbContext _context;
 
-        public BookService(LibraryManagementContext context)
+        public BookService(AppDbContext context)
         {
             _context = context;
         }

Backend/Features/Borrowing/BorrowingController.cs

@@ -24,7 +24,7 @@ namespace Backend.Features.Borrowings
                 var userIdStr = User.FindFirstValue(ClaimTypes.NameIdentifier);
                 if (string.IsNullOrEmpty(userIdStr)) return Unauthorized();
 
-                var userId = int.Parse(userIdStr);
+                var userId = Guid.Parse(userIdStr);
                 var borrowing = await _borrowingService.BorrowBookAsync(userId, request.BookId);
                 return Ok(borrowing);
             }
@@ -36,7 +36,7 @@ namespace Backend.Features.Borrowings
 
         [HttpPost("return-request/{id}")]
         [Authorize]
-        public async Task<ActionResult<BorrowingDto>> RequestReturn(int id)
+        public async Task<ActionResult<BorrowingDto>> RequestReturn(Guid id)
         {
             try
             {
@@ -51,7 +51,7 @@ namespace Backend.Features.Borrowings
 
         [HttpPost("return/{id}")]
         [Authorize(Roles = "Librarian")]
-        public async Task<ActionResult<BorrowingDto>> ReturnBook(int id)
+        public async Task<ActionResult<BorrowingDto>> ReturnBook(Guid id)
         {
             try
             {
@@ -71,7 +71,7 @@ namespace Backend.Features.Borrowings
             var userIdStr = User.FindFirstValue(ClaimTypes.NameIdentifier);
             if (string.IsNullOrEmpty(userIdStr)) return Unauthorized();
 
-            var userId = int.Parse(userIdStr);
+            var userId = Guid.Parse(userIdStr);
             var borrowings = await _borrowingService.GetUserBorrowingsAsync(userId);
             return Ok(borrowings);
         }

Backend/Features/Borrowing/BorrowingModels.cs

@@ -4,8 +4,8 @@ namespace Backend.Features.Borrowings
 {
     public class BorrowingDto
     {
-        public int Id { get; set; }
-        public int UserId { get; set; }
+        public Guid Id { get; set; }
+        public Guid UserId { get; set; }
         public string UserEmail { get; set; } = string.Empty;
         public int BookId { get; set; }
         public string BookTitle { get; set; } = string.Empty;

Backend/Features/Borrowing/BorrowingService.cs

@@ -1,4 +1,5 @@
-using Database.Models;
+using DbConnect.Data;
+using DbConnect.Entities;
 using Microsoft.EntityFrameworkCore;
 using Backend.Features.Loyalty;
 
@@ -6,26 +7,26 @@ namespace Backend.Features.Borrowings
 {
     public interface IBorrowingService
     {
-        Task<BorrowingDto> BorrowBookAsync(int userId, int bookId);
-        Task<BorrowingDto> RequestReturnAsync(int borrowingId);
-        Task<BorrowingDto> ReturnBookAsync(int borrowingId);
-        Task<IEnumerable<BorrowingDto>> GetUserBorrowingsAsync(int userId);
+        Task<BorrowingDto> BorrowBookAsync(Guid userId, int bookId);
+        Task<BorrowingDto> RequestReturnAsync(Guid borrowingId);
+        Task<BorrowingDto> ReturnBookAsync(Guid borrowingId);
+        Task<IEnumerable<BorrowingDto>> GetUserBorrowingsAsync(Guid userId);
         Task<IEnumerable<BorrowingDto>> GetAllBorrowingsAsync();
     }
 
     public class BorrowingService : IBorrowingService
     {
-        private readonly LibraryManagementContext _context;
+        private readonly AppDbContext _context;
         private readonly ILoyaltyService _loyaltyService;
         private const decimal FinePerDay = 500;
 
-        public BorrowingService(LibraryManagementContext context, ILoyaltyService loyaltyService)
+        public BorrowingService(AppDbContext context, ILoyaltyService loyaltyService)
         {
             _context = context;
             _loyaltyService = loyaltyService;
         }
 
-        public async Task<BorrowingDto> BorrowBookAsync(int userId, int bookId)
+        public async Task<BorrowingDto> BorrowBookAsync(Guid userId, int bookId)
         {
             // 1. Check for Active Membership
             var subscription = await _context.UserSubscriptions
@@ -95,7 +96,7 @@ namespace Backend.Features.Borrowings
             return MapToDto(borrowing);
         }
 
-        public async Task<BorrowingDto> RequestReturnAsync(int borrowingId)
+        public async Task<BorrowingDto> RequestReturnAsync(Guid borrowingId)
         {
             var borrowing = await _context.Borrowings
                 .Include(b => b.Book)
@@ -110,7 +111,7 @@ namespace Backend.Features.Borrowings
             return MapToDto(borrowing);
         }
 
-        public async Task<BorrowingDto> ReturnBookAsync(int borrowingId)
+        public async Task<BorrowingDto> ReturnBookAsync(Guid borrowingId)
         {
             var borrowing = await _context.Borrowings
                 .Include(b => b.Book)
@@ -159,7 +160,7 @@ namespace Backend.Features.Borrowings
             return MapToDto(borrowing);
         }
 
-        public async Task<IEnumerable<BorrowingDto>> GetUserBorrowingsAsync(int userId)
+        public async Task<IEnumerable<BorrowingDto>> GetUserBorrowingsAsync(Guid userId)
         {
             var borrowings = await _context.Borrowings
                 .Include(b => b.Book)

Backend/Features/Categories/CategoryService.cs

@@ -1,4 +1,5 @@
-using Database.Models;
+using DbConnect.Data;
+using DbConnect.Entities;
 using Microsoft.EntityFrameworkCore;
 
 namespace Backend.Features.Categories
@@ -13,9 +14,9 @@ namespace Backend.Features.Categories
 
     public class CategoryService : ICategoryService
     {
-        private readonly LibraryManagementContext _context;
+        private readonly AppDbContext _context;
 
-        public CategoryService(LibraryManagementContext context)
+        public CategoryService(AppDbContext context)
         {
             _context = context;
         }

Backend/Features/Loyalty/LoyaltyController.cs

@@ -101,7 +101,7 @@ namespace Backend.Features.Loyalty
 
             // 3. side effect: Grant membership in the library system
             bool membershipGranted = false;
-            if (int.TryParse(redemption.ExternalUserId?.Trim(), out int userId))
+            if (Guid.TryParse(redemption.ExternalUserId?.Trim(), out Guid userId))
             {
                 System.Diagnostics.Debug.WriteLine($"Fulfilling redemption {id} for user {userId}. RewardId: '{redemption.RewardId}', RewardName: '{redemption.RewardName}'");
                 membershipGranted = await _subscriptionService.HandleLoyaltyRedemptionAsync(userId, redemption.RewardId, redemption.RewardName, redemption.Id);

Backend/Features/Subscriptions/SubscriptionController.cs

@@ -29,7 +29,7 @@ namespace Backend.Features.Subscriptions
             var userIdStr = User.FindFirstValue(ClaimTypes.NameIdentifier);
             if (string.IsNullOrEmpty(userIdStr)) return Unauthorized();
 
-            var userId = int.Parse(userIdStr);
+            var userId = Guid.Parse(userIdStr);
             var subscription = await _subscriptionService.GetUserSubscriptionAsync(userId);
             
             if (subscription == null) return NotFound(new { message = "No active subscription found." });
@@ -44,7 +44,7 @@ namespace Backend.Features.Subscriptions
             var userIdStr = User.FindFirstValue(ClaimTypes.NameIdentifier);
             if (string.IsNullOrEmpty(userIdStr)) return Unauthorized();
 
-            var userId = int.Parse(userIdStr);
+            var userId = Guid.Parse(userIdStr);
             var subscriptions = await _subscriptionService.GetUserAllSubscriptionsAsync(userId);
             return Ok(subscriptions);
         }
@@ -58,7 +58,7 @@ namespace Backend.Features.Subscriptions
                 var userIdStr = User.FindFirstValue(ClaimTypes.NameIdentifier);
                 if (string.IsNullOrEmpty(userIdStr)) return Unauthorized();
 
-                var userId = int.Parse(userIdStr);
+                var userId = Guid.Parse(userIdStr);
                 var subscription = await _subscriptionService.SubscribeUserAsync(userId, request.MembershipId);
                 return Ok(subscription);
             }
@@ -70,7 +70,7 @@ namespace Backend.Features.Subscriptions
 
         [HttpGet("subscriptions/user/{userId}")]
         [Authorize(Roles = "Librarian")]
-        public async Task<ActionResult<SubscriptionDto>> GetUserSubscription(int userId)
+        public async Task<ActionResult<SubscriptionDto>> GetUserSubscription(Guid userId)
         {
             var subscription = await _subscriptionService.GetUserSubscriptionAsync(userId);
             if (subscription == null) return NotFound(new { message = "No active subscription found." });

Backend/Features/Subscriptions/SubscriptionModels.cs

@@ -16,8 +16,8 @@ namespace Backend.Features.Subscriptions
 
     public class SubscriptionDto
     {
-        public int Id { get; set; }
-        public int UserId { get; set; }
+        public Guid Id { get; set; }
+        public Guid UserId { get; set; }
         public int MembershipId { get; set; }
         public string MembershipType { get; set; } = string.Empty;
         public string UserEmail { get; set; } = string.Empty;
@@ -35,7 +35,7 @@ namespace Backend.Features.Subscriptions
 
     public class AdminSubscribeRequest
     {
-        public int UserId { get; set; }
+        public Guid UserId { get; set; }
         public int MembershipId { get; set; }
     }
 }

Backend/Features/Subscriptions/SubscriptionService.cs

@@ -1,4 +1,5 @@
-using Database.Models;
+using DbConnect.Data;
+using DbConnect.Entities;
 using Microsoft.EntityFrameworkCore;
 using Backend.Features.Loyalty;
 
@@ -7,19 +8,19 @@ namespace Backend.Features.Subscriptions
     public interface ISubscriptionService
     {
         Task<IEnumerable<MembershipDto>> GetMembershipsAsync();
-        Task<SubscriptionDto?> GetUserSubscriptionAsync(int userId);
-        Task<IEnumerable<SubscriptionDto>> GetUserAllSubscriptionsAsync(int userId);
-        Task<bool> HandleLoyaltyRedemptionAsync(int userId, string rewardId, string rewardName, string redemptionId);
-        Task<SubscriptionDto> SubscribeUserAsync(int userId, int membershipId);
+        Task<SubscriptionDto?> GetUserSubscriptionAsync(Guid userId);
+        Task<IEnumerable<SubscriptionDto>> GetUserAllSubscriptionsAsync(Guid userId);
+        Task<bool> HandleLoyaltyRedemptionAsync(Guid userId, string rewardId, string rewardName, string redemptionId);
+        Task<SubscriptionDto> SubscribeUserAsync(Guid userId, int membershipId);
         Task<IEnumerable<SubscriptionDto>> GetAllSubscriptionsAsync();
     }
 
     public class SubscriptionService : ISubscriptionService
     {
-        private readonly LibraryManagementContext _context;
+        private readonly AppDbContext _context;
         private readonly ILoyaltyService _loyaltyService;
 
-        public SubscriptionService(LibraryManagementContext context, ILoyaltyService loyaltyService)
+        public SubscriptionService(AppDbContext context, ILoyaltyService loyaltyService)
         {
             _context = context;
             _loyaltyService = loyaltyService;
@@ -40,7 +41,7 @@ namespace Backend.Features.Subscriptions
                 }).ToListAsync();
         }
 
-        public async Task<SubscriptionDto?> GetUserSubscriptionAsync(int userId)
+        public async Task<SubscriptionDto?> GetUserSubscriptionAsync(Guid userId)
         {
             var subscription = await _context.UserSubscriptions
                 .Include(s => s.Membership)
@@ -53,7 +54,7 @@ namespace Backend.Features.Subscriptions
             return MapToDto(subscription);
         }
 
-        public async Task<IEnumerable<SubscriptionDto>> GetUserAllSubscriptionsAsync(int userId)
+        public async Task<IEnumerable<SubscriptionDto>> GetUserAllSubscriptionsAsync(Guid userId)
         {
             var subscriptions = await _context.UserSubscriptions
                 .Include(s => s.Membership)
@@ -65,7 +66,7 @@ namespace Backend.Features.Subscriptions
             return subscriptions.Select(MapToDto);
         }
 
-        public async Task<bool> HandleLoyaltyRedemptionAsync(int userId, string rewardId, string rewardName, string redemptionId)
+        public async Task<bool> HandleLoyaltyRedemptionAsync(Guid userId, string rewardId, string rewardName, string redemptionId)
         {
             try
             {
@@ -112,7 +113,7 @@ namespace Backend.Features.Subscriptions
             }
         }
 
-        public async Task<SubscriptionDto> SubscribeUserAsync(int userId, int membershipId)
+        public async Task<SubscriptionDto> SubscribeUserAsync(Guid userId, int membershipId)
         {
             var membership = await _context.Memberships.FindAsync(membershipId);
             if (membership == null) throw new Exception("Membership plan not found.");

Backend/Features/Users/UserController.cs

@@ -24,7 +24,7 @@ namespace Backend.Features.Users
 
         [HttpGet("{id}")]
         [Authorize(Roles = "Librarian")]
-        public async Task<ActionResult<UserDto>> GetUser(int id)
+        public async Task<ActionResult<UserDto>> GetUser(Guid id)
         {
             var user = await _userService.GetUserByIdAsync(id);
             if (user == null) return NotFound();
@@ -48,7 +48,7 @@ namespace Backend.Features.Users
 
         [HttpPut("{id}")]
         [Authorize(Roles = "Librarian")]
-        public async Task<ActionResult<UserDto>> UpdateUser(int id, [FromBody] UserUpdateRequest request)
+        public async Task<ActionResult<UserDto>> UpdateUser(Guid id, [FromBody] UserUpdateRequest request)
         {
             var updatedUser = await _userService.UpdateUserAsync(id, request);
             if (updatedUser == null) return NotFound();
@@ -57,7 +57,7 @@ namespace Backend.Features.Users
 
         [HttpPatch("{id}/role")]
         [Authorize(Roles = "Librarian")]
-        public async Task<IActionResult> UpdateUserRole(int id, [FromBody] UserRoleUpdateRequest request)
+        public async Task<IActionResult> UpdateUserRole(Guid id, [FromBody] UserRoleUpdateRequest request)
         {
             var success = await _userService.UpdateUserRoleAsync(id, request.Role);
             if (!success) return NotFound();
@@ -66,7 +66,7 @@ namespace Backend.Features.Users
 
         [HttpDelete("{id}")]
         [Authorize(Roles = "Librarian")]
-        public async Task<IActionResult> DeleteUser(int id)
+        public async Task<IActionResult> DeleteUser(Guid id)
         {
             var success = await _userService.DeleteUserAsync(id);
             if (!success) return NotFound();

Backend/Features/Users/UserService.cs

@@ -1,4 +1,5 @@
-using Database.Models;
+using DbConnect.Data;
+using DbConnect.Entities;
 using Microsoft.EntityFrameworkCore;
 using Backend.Features.Subscriptions;
 using Backend.Features.Loyalty;
@@ -12,20 +13,20 @@ namespace Backend.Features.Users
     public interface IUserService
     {
         Task<IEnumerable<UserDto>> GetAllUsersAsync();
-        Task<UserDto?> GetUserByIdAsync(int id);
+        Task<UserDto?> GetUserByIdAsync(Guid id);
         Task<UserDto> CreateUserAsync(UserCreateRequest request);
-        Task<UserDto?> UpdateUserAsync(int id, UserUpdateRequest request);
-        Task<bool> UpdateUserRoleAsync(int id, string role);
-        Task<bool> DeleteUserAsync(int id);
+        Task<UserDto?> UpdateUserAsync(Guid id, UserUpdateRequest request);
+        Task<bool> UpdateUserRoleAsync(Guid id, string role);
+        Task<bool> DeleteUserAsync(Guid id);
     }
 
     public class UserService : IUserService
     {
-        private readonly LibraryManagementContext _context;
+        private readonly AppDbContext _context;
         private readonly ISubscriptionService _subscriptionService;
         private readonly ILoyaltyService _loyaltyService;
 
-        public UserService(LibraryManagementContext context, ISubscriptionService subscriptionService, ILoyaltyService loyaltyService)
+        public UserService(AppDbContext context, ISubscriptionService subscriptionService, ILoyaltyService loyaltyService)
         {
             _context = context;
             _subscriptionService = subscriptionService;
@@ -38,7 +39,7 @@ namespace Backend.Features.Users
             return users.Select(MapToDto);
         }
 
-        public async Task<UserDto?> GetUserByIdAsync(int id)
+        public async Task<UserDto?> GetUserByIdAsync(Guid id)
         {
             var user = await _context.Users.FindAsync(id);
             return user == null ? null : MapToDto(user);
@@ -89,7 +90,7 @@ namespace Backend.Features.Users
             return MapToDto(user);
         }
 
-        public async Task<UserDto?> UpdateUserAsync(int id, UserUpdateRequest request)
+        public async Task<UserDto?> UpdateUserAsync(Guid id, UserUpdateRequest request)
         {
             var user = await _context.Users.FindAsync(id);
             if (user == null) return null;
@@ -112,7 +113,7 @@ namespace Backend.Features.Users
             return MapToDto(user);
         }
 
-        public async Task<bool> UpdateUserRoleAsync(int id, string role)
+        public async Task<bool> UpdateUserRoleAsync(Guid id, string role)
         {
             var user = await _context.Users.FindAsync(id);
             if (user == null) return false;
@@ -124,7 +125,7 @@ namespace Backend.Features.Users
             return true;
         }
 
-        public async Task<bool> DeleteUserAsync(int id)
+        public async Task<bool> DeleteUserAsync(Guid id)
         {
             var user = await _context.Users.FindAsync(id);
             if (user == null) return false;
@@ -159,7 +160,7 @@ namespace Backend.Features.Users
 
     public class UserDto
     {
-        public int Id { get; set; }
+        public Guid Id { get; set; }
         public string Name => FullName;
         public string FullName { get; set; } = string.Empty;
         public string Email { get; set; } = string.Empty;

Backend/Program.cs

@@ -1,5 +1,6 @@
 using System.Text;
-using Database.Models;
+using DbConnect.Data;
+using DbConnect.Entities;
 using Backend.Features.Auth;
 using Backend.Features.Users;
 using Backend.Features.Books;
@@ -46,7 +47,7 @@ builder.Services.AddSwaggerGen(c =>
     });
 });
 
-builder.Services.AddDbContext<LibraryManagementContext>(options =>
+builder.Services.AddDbContext<AppDbContext>(options =>
     options.UseSqlServer(builder.Configuration.GetConnectionString("MssqlConnection")));
 
 // Register Services

Database/Models/Wishlist.cs

@@ -1,17 +0,0 @@
-using System;
-using System.Collections.Generic;
-
-namespace Database.Models;
-
-public partial class Wishlist
-{
-    public int Id { get; set; }
-
-    public int UserId { get; set; }
-
-    public int BookId { get; set; }
-
-    public virtual Book Book { get; set; } = null!;
-
-    public virtual User User { get; set; } = null!;
-}

Database/add_reward_id_to_memberships.sql

@@ -1,14 +0,0 @@
-USE LibraryManagement;
-GO
-
--- Add RewardId column if it doesn't exist
-IF NOT EXISTS (SELECT * FROM sys.columns WHERE object_id = OBJECT_ID('Memberships') AND name = 'RewardId')
-BEGIN
-    ALTER TABLE Memberships ADD RewardId NVARCHAR(50) NULL;
-END
-GO
-
--- Populate RewardId for existing memberships
-UPDATE Memberships SET RewardId = '39aff010-693e-450e-85e7-ae6c3f1a2078' WHERE Type = 'Basic Monthly';
-UPDATE Memberships SET RewardId = '94bc0b20-1a87-4e10-a778-dd48552470d0' WHERE Type = 'Basic Yearly';
-GO

Database/db.sql

@@ -1,112 +0,0 @@
--- Library Management System Database Schema (MSSQL)
-CREATE DATABASE LibraryManagement;
-GO
-
-USE LibraryManagement;
-GO
-
--- 1. Categories Table
-CREATE TABLE Categories (
-    Id INT IDENTITY(1,1) PRIMARY KEY,
-    Name NVARCHAR(100) NOT NULL,
-    CONSTRAINT UQ_Categories_Name UNIQUE (Name)
-);
-GO
-
--- 2. Books Table
-CREATE TABLE Books (
-    Id INT IDENTITY(1,1) PRIMARY KEY,
-    Title NVARCHAR(200) NOT NULL,
-    ISBN NVARCHAR(20) NOT NULL,
-    Author NVARCHAR(100) NOT NULL,
-    Status NVARCHAR(20) NOT NULL DEFAULT 'Available',
-    IsActive BIT NOT NULL DEFAULT 1,
-    CreatedAt DATETIME NOT NULL DEFAULT (GETDATE()),
-    Description NVARCHAR(MAX) NULL,
-    TotalCopies INT NOT NULL DEFAULT 1,
-    AvailableCopies INT NOT NULL DEFAULT 1,
-    UpdatedAt DATETIME NULL,
-    CONSTRAINT UQ_Books_ISBN UNIQUE (ISBN)
-);
-GO
-
--- 3. Users Table
-CREATE TABLE Users (
-    Id INT IDENTITY(1,1) PRIMARY KEY,
-    FullName NVARCHAR(100) NOT NULL,
-    Email NVARCHAR(100) NOT NULL,
-    PasswordHash NVARCHAR(MAX) NOT NULL,
-    PhoneNumber NVARCHAR(20) NULL,
-    Role NVARCHAR(20) NOT NULL DEFAULT 'Member',
-    IsActive BIT NOT NULL DEFAULT 1,
-    CreatedAt DATETIME NOT NULL DEFAULT (GETDATE()),
-    UpdatedAt DATETIME NULL,
-    StudentId NVARCHAR(20) NULL,
-    BanStatus BIT NULL,
-    SuspensionEndDate DATETIME NULL,
-    Address NVARCHAR(255) NULL,
-    CONSTRAINT UQ_Users_Email UNIQUE (Email)
-);
-GO
-
--- 4. Memberships Table
-CREATE TABLE Memberships (
-    Id INT IDENTITY(1,1) PRIMARY KEY,
-    Type NVARCHAR(50) NOT NULL,
-    MaxBooks INT NOT NULL,
-    BorrowingDays INT NOT NULL,
-    Price DECIMAL(10, 2) NOT NULL,
-    DurationMonths INT NOT NULL,
-    LoyaltyRewardId NVARCHAR(50) NULL,
-    CONSTRAINT IX_Memberships_Type UNIQUE (Type)
-);
-GO
-
--- 5. BookCategories (Many-to-Many Join Table)
-CREATE TABLE BookCategories (
-    BookId INT NOT NULL,
-    CategoryId INT NOT NULL,
-    CONSTRAINT PK_BookCategories PRIMARY KEY (BookId, CategoryId),
-    CONSTRAINT FK_BookCategories_Books FOREIGN KEY (BookId) REFERENCES Books(Id) ON DELETE CASCADE,
-    CONSTRAINT FK_BookCategories_Categories FOREIGN KEY (CategoryId) REFERENCES Categories(Id) ON DELETE CASCADE
-);
-GO
-
--- 6. Borrowings Table
-CREATE TABLE Borrowings (
-    Id INT IDENTITY(1,1) PRIMARY KEY,
-    UserId INT NOT NULL,
-    BookId INT NOT NULL,
-    BorrowDate DATETIME NOT NULL DEFAULT (GETDATE()),
-    DueDate DATETIME NOT NULL,
-    ReturnDate DATETIME NULL,
-    Status NVARCHAR(20) NOT NULL DEFAULT 'Active',
-    FineAmount DECIMAL(10, 2) NOT NULL DEFAULT 0.00,
-    IsFinePaid BIT NOT NULL DEFAULT 0,
-    CONSTRAINT FK_Borrowings_Users FOREIGN KEY (UserId) REFERENCES Users(Id),
-    CONSTRAINT FK_Borrowings_Books FOREIGN KEY (BookId) REFERENCES Books(Id)
-);
-GO
-
--- 7. UserSubscriptions Table
-CREATE TABLE UserSubscriptions (
-    Id INT IDENTITY(1,1) PRIMARY KEY,
-    UserId INT NOT NULL,
-    MembershipId INT NOT NULL,
-    StartDate DATETIME NOT NULL,
-    ExpiryDate DATETIME NOT NULL,
-    IsActive BIT NOT NULL DEFAULT 1,
-    CONSTRAINT FK_UserSubscriptions_Users FOREIGN KEY (UserId) REFERENCES Users(Id),
-    CONSTRAINT FK_UserSubscriptions_Memberships FOREIGN KEY (MembershipId) REFERENCES Memberships(Id)
-);
-GO
-
--- 8. Wishlists Table
-CREATE TABLE Wishlists (
-    Id INT IDENTITY(1,1) PRIMARY KEY,
-    UserId INT NOT NULL,
-    BookId INT NOT NULL,
-    CONSTRAINT FK_Wishlists_Users FOREIGN KEY (UserId) REFERENCES Users(Id),
-    CONSTRAINT FK_Wishlists_Books FOREIGN KEY (BookId) REFERENCES Books(Id)
-);
-GO

Database/seed_data.sql

@@ -1,86 +0,0 @@
--- Seed Data for Library Management System
-USE LibraryManagement;
-GO
-
--- 1. Insert Categories
-SET IDENTITY_INSERT Categories ON;
-INSERT INTO Categories (Id, Name) VALUES 
-(1, 'Fiction'),
-(2, 'Science'),
-(3, 'History'),
-(4, 'Biography'),
-(5, 'Technology'),
-(6, 'Philosophy'),
-(7, 'Self-Help'),
-(8, 'Fantasy'),
-(9, 'Mystery'),
-(10, 'Business');
-SET IDENTITY_INSERT Categories OFF;
-GO
-
--- 2. Insert Memberships
-SET IDENTITY_INSERT Memberships ON;
-INSERT INTO Memberships (Id, Type, MaxBooks, BorrowingDays, Price, DurationMonths) VALUES 
-(1, 'Basic', 2, 7, 10.00, 1),
-(2, 'Standard', 5, 14, 25.00, 3),
-(3, 'Premium', 10, 30, 80.00, 12),
-(4, 'Student', 3, 15, 15.00, 6);
-SET IDENTITY_INSERT Memberships OFF;
-GO
-
--- 3. Insert Users (Password is 'Password123' hashed typically, but using placeholder for SQL)
-SET IDENTITY_INSERT Users ON;
-INSERT INTO Users (Id, FullName, Email, PasswordHash, PhoneNumber, Role, IsActive, CreatedAt, Address) VALUES 
-(1, 'Admin User', 'admin@library.com', 'AQAAAAEAACcQAAAAE...', '09123456789', 'Admin', 1, GETDATE(), '123 Main St, Central City'),
-(2, 'John Doe', 'john.doe@gmail.com', 'AQAAAAEAACcQAAAAE...', '09234567890', 'Member', 1, GETDATE(), '456 Oak Ave, North Side'),
-(3, 'Jane Smith', 'jane.smith@yahoo.com', 'AQAAAAEAACcQAAAAE...', '09345678901', 'Member', 1, GETDATE(), '789 Pine Rd, South Village'),
-(4, 'David Wilson', 'david.w@university.edu', 'AQAAAAEAACcQAAAAE...', '09456789012', 'Member', 1, GETDATE(), '101 University Dr, Campus'),
-(5, 'Sarah Miller', 'sarah.m@gmail.com', 'AQAAAAEAACcQAAAAE...', '09567890123', 'Member', 1, GETDATE(), '202 Lake View, West Coast');
-SET IDENTITY_INSERT Users OFF;
-GO
-
--- 4. Insert Books
-SET IDENTITY_INSERT Books ON;
-INSERT INTO Books (Id, Title, ISBN, Author, Status, IsActive, CreatedAt, Description, TotalCopies, AvailableCopies) VALUES 
-(1, 'The Great Gatsby', '9780743273565', 'F. Scott Fitzgerald', 'Available', 1, GETDATE(), 'A classic novel of the Jazz Age.', 5, 5),
-(2, 'A Brief History of Time', '9780553380163', 'Stephen Hawking', 'Available', 1, GETDATE(), 'Exploring the origin and fate of the universe.', 3, 3),
-(3, 'Steve Jobs', '9781451648539', 'Walter Isaacson', 'Available', 1, GETDATE(), 'The exclusive biography of Steve Jobs.', 2, 2),
-(4, 'The Pragmatic Programmer', '9780135957059', 'Andrew Hunt', 'Available', 1, GETDATE(), 'Your journey to mastery in software development.', 4, 4),
-(5, 'Sapiens', '9780062316097', 'Yuval Noah Harari', 'Available', 1, GETDATE(), 'A brief history of humankind.', 6, 6),
-(6, 'The Hobbit', '9780547928227', 'J.R.R. Tolkien', 'Available', 1, GETDATE(), 'A prelude to The Lord of the Rings.', 8, 8),
-(7, 'Atomic Habits', '9780735211292', 'James Clear', 'Available', 1, GETDATE(), 'An easy & proven way to build good habits.', 10, 10),
-(8, 'The Da Vinci Code', '9780307474278', 'Dan Brown', 'Available', 1, GETDATE(), 'A murder in the Louvre leads to a complex mystery.', 5, 5),
-(9, 'Lean In', '9780385349949', 'Sheryl Sandberg', 'Available', 1, GETDATE(), 'Women, work, and the will to lead.', 3, 3),
-(10, 'Clean Code', '9780132350884', 'Robert C. Martin', 'Available', 1, GETDATE(), 'A handbook of agile software craftsmanship.', 4, 4);
-SET IDENTITY_INSERT Books OFF;
-GO
-
--- 5. Book-Category Mapping
-INSERT INTO BookCategories (BookId, CategoryId) VALUES 
-(1, 1), -- Great Gatsby - Fiction
-(2, 2), -- Brief History - Science
-(3, 4), -- Steve Jobs - Biography
-(4, 5), -- Pragmatic Programmer - Technology
-(5, 3), -- Sapiens - History
-(6, 8), -- Hobbit - Fantasy
-(7, 7), -- Atomic Habits - Self-Help
-(8, 9), -- Da Vinci Code - Mystery
-(9, 10), -- Lean In - Business
-(10, 5); -- Clean Code - Technology
-GO
-
--- 6. User Subscriptions
-INSERT INTO UserSubscriptions (UserId, MembershipId, StartDate, ExpiryDate, IsActive) VALUES 
-(2, 2, '2026-01-01', '2026-04-01', 1),
-(3, 3, '2026-01-01', '2027-01-01', 1),
-(4, 4, '2026-02-15', '2026-08-15', 1),
-(5, 1, '2026-04-01', '2026-05-01', 1);
-GO
-
--- 7. Some Borrowing History
-INSERT INTO Borrowings (UserId, BookId, BorrowDate, DueDate, ReturnDate, Status) VALUES 
-(2, 1, '2026-04-10', '2026-04-24', '2026-04-15', 'Returned'),
-(2, 4, '2026-04-16', '2026-04-30', NULL, 'Active'),
-(3, 7, '2026-04-01', '2026-05-01', NULL, 'Active'),
-(4, 10, '2026-04-18', '2026-05-03', NULL, 'Active');
-GO

DbConnect/Class1.cs

@@ -0,0 +1,7 @@
+namespace DbConnect
+{
+    public class Class1
+    {
+
+    }
+}

Database/Models/LibraryManagementContext.cs → DbConnect/Data/AppDbContext.cs

@@ -1,16 +1,17 @@
-using System;
+using System;
 using System.Collections.Generic;
+using DbConnect.Entities;
 using Microsoft.EntityFrameworkCore;
 
-namespace Database.Models;
+namespace DbConnect.Data;
 
-public partial class LibraryManagementContext : DbContext
+public partial class AppDbContext : DbContext
 {
-    public LibraryManagementContext()
+    public AppDbContext()
     {
     }
 
-    public LibraryManagementContext(DbContextOptions<LibraryManagementContext> options)
+    public AppDbContext(DbContextOptions<AppDbContext> options)
         : base(options)
     {
     }
@@ -27,7 +28,9 @@ public partial class LibraryManagementContext : DbContext
 
     public virtual DbSet<UserSubscription> UserSubscriptions { get; set; }
 
-    public virtual DbSet<Wishlist> Wishlists { get; set; }
+    protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
+#warning To protect potentially sensitive information in your connection string, you should move it out of source code. You can avoid scaffolding the connection string by using the Name= syntax to read it from configuration - see https://go.microsoft.com/fwlink/?linkid=2131148. For more guidance on storing connection strings, see https://go.microsoft.com/fwlink/?LinkId=723263.
+        => optionsBuilder.UseSqlServer("Server=.;Database=LibraryManagement;User Id=sa;Password=sasa@123;TrustServerCertificate=True;");
 
     protected override void OnModelCreating(ModelBuilder modelBuilder)
     {
@@ -38,6 +41,7 @@ public partial class LibraryManagementContext : DbContext
             entity.HasIndex(e => e.Isbn, "UQ__Books__447D36EA79CF66CE").IsUnique();
 
             entity.Property(e => e.Author).HasMaxLength(100);
+            entity.Property(e => e.AvailableCopies).HasDefaultValue(1);
             entity.Property(e => e.CreatedAt)
                 .HasDefaultValueSql("(getdate())")
                 .HasColumnType("datetime");
@@ -50,7 +54,6 @@ public partial class LibraryManagementContext : DbContext
                 .HasDefaultValue("Available");
             entity.Property(e => e.Title).HasMaxLength(200);
             entity.Property(e => e.TotalCopies).HasDefaultValue(1);
-            entity.Property(e => e.AvailableCopies).HasDefaultValue(1);
             entity.Property(e => e.UpdatedAt).HasColumnType("datetime");
 
             entity.HasMany(d => d.Categories).WithMany(p => p.Books)
@@ -71,8 +74,7 @@ public partial class LibraryManagementContext : DbContext
 
         modelBuilder.Entity<Borrowing>(entity =>
         {
-            entity.HasKey(e => e.Id).HasName("PK__Borrowin__3214EC07EA26D8CD");
-
+            entity.Property(e => e.Id).HasDefaultValueSql("(newid())");
             entity.Property(e => e.BorrowDate)
                 .HasDefaultValueSql("(getdate())")
                 .HasColumnType("datetime");
@@ -110,15 +112,15 @@ public partial class LibraryManagementContext : DbContext
             entity.HasIndex(e => e.Type, "IX_Memberships_Type").IsUnique();
 
             entity.Property(e => e.Price).HasColumnType("decimal(10, 2)");
+            entity.Property(e => e.RewardId).HasMaxLength(100);
             entity.Property(e => e.Type).HasMaxLength(50);
         });
 
         modelBuilder.Entity<User>(entity =>
         {
-            entity.HasKey(e => e.Id).HasName("PK__Users__3214EC0771D7BED2");
-
-            entity.HasIndex(e => e.Email, "UQ__Users__A9D10534F91FFF73").IsUnique();
+            entity.HasIndex(e => e.Email, "UQ_Users_Email").IsUnique();
 
+            entity.Property(e => e.Id).HasDefaultValueSql("(newid())");
             entity.Property(e => e.Address).HasMaxLength(255);
             entity.Property(e => e.CreatedAt)
                 .HasDefaultValueSql("(getdate())")
@@ -129,7 +131,7 @@ public partial class LibraryManagementContext : DbContext
             entity.Property(e => e.PhoneNumber).HasMaxLength(20);
             entity.Property(e => e.Role)
                 .HasMaxLength(20)
-                .HasDefaultValue("Member");
+                .HasDefaultValue("User");
             entity.Property(e => e.StudentId).HasMaxLength(20);
             entity.Property(e => e.SuspensionEndDate).HasColumnType("datetime");
             entity.Property(e => e.UpdatedAt).HasColumnType("datetime");
@@ -137,11 +139,14 @@ public partial class LibraryManagementContext : DbContext
 
         modelBuilder.Entity<UserSubscription>(entity =>
         {
-            entity.HasKey(e => e.Id).HasName("PK__UserSubs__3214EC07E3FBC0EC");
-
+            entity.Property(e => e.Id).HasDefaultValueSql("(newid())");
             entity.Property(e => e.ExpiryDate).HasColumnType("datetime");
+            entity.Property(e => e.ExternalRedemptionId).HasMaxLength(100);
             entity.Property(e => e.IsActive).HasDefaultValue(true);
             entity.Property(e => e.StartDate).HasColumnType("datetime");
+            entity.Property(e => e.Status)
+                .HasMaxLength(20)
+                .HasDefaultValue("Active");
 
             entity.HasOne(d => d.Membership).WithMany(p => p.UserSubscriptions)
                 .HasForeignKey(d => d.MembershipId)
@@ -154,19 +159,6 @@ public partial class LibraryManagementContext : DbContext
                 .HasConstraintName("FK_UserSubscriptions_Users");
         });
 
-        modelBuilder.Entity<Wishlist>(entity =>
-        {
-            entity.HasKey(e => e.Id).HasName("PK__Wishlist__3214EC07F63D8F81");
-
-            entity.HasOne(d => d.Book).WithMany(p => p.Wishlists)
-                .HasForeignKey(d => d.BookId)
-                .HasConstraintName("FK_Wishlists_Books");
-
-            entity.HasOne(d => d.User).WithMany(p => p.Wishlists)
-                .HasForeignKey(d => d.UserId)
-                .HasConstraintName("FK_Wishlists_Users");
-        });
-
         OnModelCreatingPartial(modelBuilder);
     }
 

{Database/Models → DbConnect/Entities}/Book.cs

@@ -1,7 +1,7 @@
-using System;
+using System;
 using System.Collections.Generic;
 
-namespace Database.Models;
+namespace DbConnect.Entities;
 
 public partial class Book
 {
@@ -20,16 +20,16 @@ public partial class Book
     public DateTime CreatedAt { get; set; }
 
     public string? Description { get; set; }
-    
+
+    public string? CoverUrl { get; set; }
+
     public int TotalCopies { get; set; }
-    
+
     public int AvailableCopies { get; set; }
-    
+
     public DateTime? UpdatedAt { get; set; }
 
     public virtual ICollection<Borrowing> Borrowings { get; set; } = new List<Borrowing>();
 
-    public virtual ICollection<Wishlist> Wishlists { get; set; } = new List<Wishlist>();
-
     public virtual ICollection<Category> Categories { get; set; } = new List<Category>();
 }

{Database/Models → DbConnect/Entities}/Borrowing.cs

@@ -1,13 +1,13 @@
 using System;
 using System.Collections.Generic;
 
-namespace Database.Models;
+namespace DbConnect.Entities;
 
 public partial class Borrowing
 {
-    public int Id { get; set; }
+    public Guid Id { get; set; }
 
-    public int UserId { get; set; }
+    public Guid UserId { get; set; }
 
     public int BookId { get; set; }
 

{Database/Models → DbConnect/Entities}/Category.cs

@@ -1,7 +1,7 @@
 using System;
 using System.Collections.Generic;
 
-namespace Database.Models;
+namespace DbConnect.Entities;
 
 public partial class Category
 {

{Database/Models → DbConnect/Entities}/Membership.cs

@@ -1,7 +1,7 @@
-using System;
+using System;
 using System.Collections.Generic;
 
-namespace Database.Models;
+namespace DbConnect.Entities;
 
 public partial class Membership
 {
@@ -16,6 +16,7 @@ public partial class Membership
     public decimal Price { get; set; }
 
     public int DurationMonths { get; set; }
+
     public string? RewardId { get; set; }
 
     public virtual ICollection<UserSubscription> UserSubscriptions { get; set; } = new List<UserSubscription>();

{Database/Models → DbConnect/Entities}/User.cs

@@ -1,11 +1,11 @@
 using System;
 using System.Collections.Generic;
 
-namespace Database.Models;
+namespace DbConnect.Entities;
 
 public partial class User
 {
-    public int Id { get; set; }
+    public Guid Id { get; set; }
 
     public string FullName { get; set; } = null!;
 
@@ -34,6 +34,4 @@ public partial class User
     public virtual ICollection<Borrowing> Borrowings { get; set; } = new List<Borrowing>();
 
     public virtual ICollection<UserSubscription> UserSubscriptions { get; set; } = new List<UserSubscription>();
-
-    public virtual ICollection<Wishlist> Wishlists { get; set; } = new List<Wishlist>();
 }

{Database/Models → DbConnect/Entities}/UserSubscription.cs

@@ -1,13 +1,13 @@
 using System;
 using System.Collections.Generic;
 
-namespace Database.Models;
+namespace DbConnect.Entities;
 
 public partial class UserSubscription
 {
-    public int Id { get; set; }
+    public Guid Id { get; set; }
 
-    public int UserId { get; set; }
+    public Guid UserId { get; set; }
 
     public int MembershipId { get; set; }
 
@@ -17,6 +17,10 @@ public partial class UserSubscription
 
     public bool IsActive { get; set; }
 
+    public string Status { get; set; } = null!;
+
+    public string? ExternalRedemptionId { get; set; }
+
     public virtual Membership Membership { get; set; } = null!;
 
     public virtual User User { get; set; } = null!;

Frontend/Controllers/BorrowingsController.cs

@@ -22,7 +22,7 @@ namespace Frontend.Controllers
         }
 
         [HttpPost]
-        public async Task<IActionResult> RequestReturn(int id)
+        public async Task<IActionResult> RequestReturn(Guid id)
         {
             var success = await _apiClient.RequestReturnAsync(id);
             if (success)
@@ -76,7 +76,7 @@ namespace Frontend.Controllers
 
         [HttpPost]
         [Authorize(Roles = "Librarian")]
-        public async Task<IActionResult> Return(int id, bool fromManage = false)
+        public async Task<IActionResult> Return(Guid id, bool fromManage = false)
         {
             var result = await _apiClient.ReturnBookAsync(id);
             if (result != null)

Frontend/Controllers/MembersController.cs

@@ -35,7 +35,7 @@ namespace Frontend.Controllers
             return View(pagedResult);
         }
 
-        public async Task<IActionResult> Details(int id)
+        public async Task<IActionResult> Details(Guid id)
         {
             var user = await _apiClient.GetUserAsync(id);
             if (user == null) return NotFound();
@@ -54,7 +54,7 @@ namespace Frontend.Controllers
         }
 
         [HttpPost]
-        public async Task<IActionResult> AssignSubscription(int id, int membershipId)
+        public async Task<IActionResult> AssignSubscription(Guid id, int membershipId)
         {
             var request = new AdminSubscribeRequest { UserId = id, MembershipId = membershipId };
             var result = await _apiClient.AdminSubscribeAsync(request);
@@ -92,7 +92,7 @@ namespace Frontend.Controllers
         }
 
         [HttpGet]
-        public async Task<IActionResult> Edit(int id)
+        public async Task<IActionResult> Edit(Guid id)
         {
             var user = await _apiClient.GetUserAsync(id);
             if (user == null) return NotFound();
@@ -107,7 +107,7 @@ namespace Frontend.Controllers
         }
 
         [HttpPost]
-        public async Task<IActionResult> Edit(int id, UserUpdateRequest request)
+        public async Task<IActionResult> Edit(Guid id, UserUpdateRequest request)
         {
             if (!ModelState.IsValid) return View(request);
 
@@ -123,7 +123,7 @@ namespace Frontend.Controllers
         }
 
         [HttpPost]
-        public async Task<IActionResult> Delete(int id)
+        public async Task<IActionResult> Delete(Guid id)
         {
             var success = await _apiClient.DeleteUserAsync(id);
             if (success)
@@ -138,7 +138,7 @@ namespace Frontend.Controllers
         }
 
         [HttpPost]
-        public async Task<IActionResult> UpdateRole(int id, string role)
+        public async Task<IActionResult> UpdateRole(Guid id, string role)
         {
             var success = await _apiClient.UpdateUserRoleAsync(id, role);
             if (success)

Frontend/Models/Dtos/LibraryDtos.cs

@@ -72,8 +72,8 @@ namespace Frontend.Models.Dtos
     // Borrowing DTOs
     public class BorrowingDto
     {
-        public int Id { get; set; }
-        public int UserId { get; set; }
+        public Guid Id { get; set; }
+        public Guid UserId { get; set; }
         public string UserEmail { get; set; } = string.Empty;
         public int BookId { get; set; }
         public string BookTitle { get; set; } = string.Empty;
@@ -116,8 +116,8 @@ namespace Frontend.Models.Dtos
 
     public class SubscriptionDto
     {
-        public int Id { get; set; }
-        public int UserId { get; set; }
+        public Guid Id { get; set; }
+        public Guid UserId { get; set; }
         public int MembershipId { get; set; }
         public string MembershipType { get; set; } = string.Empty;
         public string UserName { get; set; } = string.Empty;
@@ -135,7 +135,7 @@ namespace Frontend.Models.Dtos
 
     public class AdminSubscribeRequest
     {
-        public int UserId { get; set; }
+        public Guid UserId { get; set; }
         public int MembershipId { get; set; }
     }
 
@@ -188,7 +188,7 @@ namespace Frontend.Models.Dtos
     // User DTOs
     public class UserDto
     {
-        public int Id { get; set; }
+        public Guid Id { get; set; }
         public string FullName { get; set; } = string.Empty;
         public string Email { get; set; } = string.Empty;
         public string? PhoneNumber { get; set; }

Frontend/Services/LibraryApiClient.cs

@@ -91,7 +91,7 @@ namespace Frontend.Services
             return response.IsSuccessStatusCode ? await response.Content.ReadFromJsonAsync<BorrowingDto>() : null;
         }
 
-        public async Task<BorrowingDto?> ReturnBookAsync(int id)
+        public async Task<BorrowingDto?> ReturnBookAsync(Guid id)
         {
             var response = await _httpClient.PostAsync($"api/borrowings/return/{id}", null);
             return response.IsSuccessStatusCode ? await response.Content.ReadFromJsonAsync<BorrowingDto>() : null;
@@ -158,7 +158,7 @@ namespace Frontend.Services
             return response.IsSuccessStatusCode ? await response.Content.ReadFromJsonAsync<SubscriptionDto>() : null;
         }
 
-        public async Task<SubscriptionDto?> GetUserSubscriptionAsync(int userId)
+        public async Task<SubscriptionDto?> GetUserSubscriptionAsync(Guid userId)
         {
             try {
                 return await _httpClient.GetFromJsonAsync<SubscriptionDto>($"api/subscriptions/user/{userId}");
@@ -208,7 +208,7 @@ namespace Frontend.Services
             } catch { return Enumerable.Empty<LoyaltyRedemptionDto>(); }
         }
 
-        public async Task<bool> RequestReturnAsync(int borrowingId)
+        public async Task<bool> RequestReturnAsync(Guid borrowingId)
         {
             var response = await _httpClient.PostAsync($"api/borrowings/return-request/{borrowingId}", null);
             return response.IsSuccessStatusCode;
@@ -269,7 +269,7 @@ namespace Frontend.Services
             return await _httpClient.GetFromJsonAsync<IEnumerable<UserDto>>("api/users") ?? Enumerable.Empty<UserDto>();
         }
 
-        public async Task<UserDto?> GetUserAsync(int id)
+        public async Task<UserDto?> GetUserAsync(Guid id)
         {
             return await _httpClient.GetFromJsonAsync<UserDto>($"api/users/{id}");
         }
@@ -280,19 +280,19 @@ namespace Frontend.Services
             return response.IsSuccessStatusCode ? await response.Content.ReadFromJsonAsync<UserDto>() : null;
         }
 
-        public async Task<UserDto?> UpdateUserAsync(int id, UserUpdateRequest request)
+        public async Task<UserDto?> UpdateUserAsync(Guid id, UserUpdateRequest request)
         {
             var response = await _httpClient.PutAsJsonAsync($"api/users/{id}", request);
             return response.IsSuccessStatusCode ? await response.Content.ReadFromJsonAsync<UserDto>() : null;
         }
 
-        public async Task<bool> UpdateUserRoleAsync(int id, string role)
+        public async Task<bool> UpdateUserRoleAsync(Guid id, string role)
         {
             var response = await _httpClient.PutAsJsonAsync($"api/users/role/{id}", new UserRoleUpdateRequest { Role = role });
             return response.IsSuccessStatusCode;
         }
 
-        public async Task<bool> DeleteUserAsync(int id)
+        public async Task<bool> DeleteUserAsync(Guid id)
         {
             var response = await _httpClient.DeleteAsync($"api/users/{id}");
             return response.IsSuccessStatusCode;

LibraryManagement.slnx

@@ -1,5 +1,5 @@
 <Solution>
   <Project Path="Backend/Backend.csproj" Id="82e311b1-ce76-4235-9d5f-0d06a942d038" />
-  <Project Path="Database/Database.csproj" Id="1ec23dc7-355d-4456-a503-cfd0fb81cd5c" />
+  <Project Path="DbConnect/DbConnect.csproj" Id="9923b718-c896-438d-ba4b-a2065f91c8ab" />
   <Project Path="Frontend/Frontend.csproj" Id="824d7fed-4fd3-41c5-8c5e-acd458ccbcdb" />
 </Solution>