commit

Tsi1.Api/Tsi1.BusinessLayer/Services/CourseService.cs

@@ -30,20 +30,22 @@ namespace Tsi1.BusinessLayer.Services
         {
             var result = new ServiceResult<Course>();
 
-            var course = _mapper.Map<Course>(newCourse);
-                
-            _context.Courses.Add(course);
-            try
-            {
-                await _context.SaveChangesAsync();
-            }
-            catch (DbUpdateException)
+            var existingCourse = await _context.Courses
+                .FirstOrDefaultAsync(x => x.Name == newCourse.Name && x.TenantId == newCourse.TenantId);
+
+            if (existingCourse != null)
             {
                 result.HasError = true;
                 result.Message = string.Format(ErrorMessages.DuplicateCourseName, newCourse.Name);
                 return result;
             }
-            
+
+            var course = _mapper.Map<Course>(newCourse);
+                
+            _context.Courses.Add(course);
+
+            await _context.SaveChangesAsync();
+
             result.Data = course;
             return result;
         }
@@ -109,25 +111,26 @@ namespace Tsi1.BusinessLayer.Services
                 return result;
             }
 
-            var studentCourse = new StudentCourse
-            {
-                Course = course,
-                Student = user.Student
-            };
-
-            _context.StudentCourses.Add(studentCourse);
+            var existingStudentCourse = await _context.StudentCourses
+                .FirstOrDefaultAsync(x => x.StudentId == user.StudentId && x.CourseId == course.Id);
 
-            try
-            {
-                await _context.SaveChangesAsync();
-            }
-            catch (DbUpdateException)
+            if (existingStudentCourse != null)
             {
                 result.HasError = true;
                 result.Message = string.Format(ErrorMessages.StudentCourseAlreadyExists, user.Username, course.Name);
                 return result;
             }
 
+            var studentCourse = new StudentCourse
+            {
+                Course = course,
+                Student = user.Student
+            };
+
+            _context.StudentCourses.Add(studentCourse);
+          
+            await _context.SaveChangesAsync();
+  
             return result;
         }
 
@@ -156,6 +159,16 @@ namespace Tsi1.BusinessLayer.Services
                 return result;
             }
 
+            var existingProfessorCourse = await _context.ProfessorCourses
+                .FirstOrDefaultAsync(x => x.ProfessorId == user.ProfessorId && x.CourseId == course.Id);
+
+            if (existingProfessorCourse != null)
+            {
+                result.HasError = true;
+                result.Message = string.Format(ErrorMessages.ProfessorCourseAlreadyExists, user.Username, course.Name);
+                return result;
+            }
+
             var professorCourse = new ProfessorCourse
             {
                 Course = course,
@@ -164,16 +177,7 @@ namespace Tsi1.BusinessLayer.Services
 
             _context.ProfessorCourses.Add(professorCourse);
 
-            try
-            {
-                await _context.SaveChangesAsync();
-            }
-            catch (DbUpdateException)
-            {
-                result.HasError = true;
-                result.Message = string.Format(ErrorMessages.ProfessorCourseAlreadyExists, user.Username, course.Name);
-                return result;
-            }
+            await _context.SaveChangesAsync();
 
             return result;
         }

Tsi1.Api/Tsi1.BusinessLayer/Services/ForumService.cs

@@ -30,21 +30,22 @@ namespace Tsi1.BusinessLayer.Services
         {
             var result = new ServiceResult<Forum>();
 
-            var forum = _mapper.Map<Forum>(newForum);
-
-            _context.Forums.Add(forum);
+            var existingForum = _context.Forums
+                .FirstOrDefaultAsync(x => x.Name == newForum.Name && x.CourseId == newForum.CourseId);
 
-            try
-            {
-                await _context.SaveChangesAsync();
-            }
-            catch (DbUpdateException)
+            if (existingForum != null)
             {
                 result.HasError = true;
                 result.Message = string.Format(ErrorMessages.DuplicateForumName, newForum.Name);
                 return result;
             }
 
+            var forum = _mapper.Map<Forum>(newForum);
+
+            _context.Forums.Add(forum);
+
+            await _context.SaveChangesAsync();
+   
             result.Data = forum;
 
             return result;
@@ -121,6 +122,16 @@ namespace Tsi1.BusinessLayer.Services
                 return result;
             }
 
+            var existingForumUser = await _context.ForumUsers
+                .FirstOrDefaultAsync(x => x.ForumId == forum.Id && x.UserId == user.Id);
+
+            if (existingForumUser != null)
+            {
+                result.HasError = true;
+                result.Message = string.Format(ErrorMessages.DuplicateForumUser, user.Username, forum.Name);
+                return result;
+            }
+
             var forumUser = new ForumUser
             {
                 ForumId = forumId,
@@ -129,16 +140,7 @@ namespace Tsi1.BusinessLayer.Services
 
             _context.ForumUsers.Add(forumUser);
 
-            try
-            {
-                await _context.SaveChangesAsync();
-            }
-            catch (DbUpdateException)
-            {
-                result.HasError = true;
-                result.Message = string.Format(ErrorMessages.DuplicateForumUser, user.Username, forum.Name);
-                return result;
-            }
+            await _context.SaveChangesAsync();
 
             return result;
         }

Tsi1.Api/Tsi1.BusinessLayer/Services/TenantService.cs

@@ -60,20 +60,20 @@ namespace Tsi1.BusinessLayer.Services
         {
             var result = new ServiceResult<TenantPreviewDto>();
 
-            var tenant = _mapper.Map<Tenant>(newTenant);
-            _context.Tenants.Add(tenant);
+            var existingTenant = await _context.Tenants.FirstOrDefaultAsync(x => x.Name == newTenant.Name);
 
-            try
-            {
-                await _context.SaveChangesAsync();
-            }
-            catch (DbUpdateException)
+            if (existingTenant != null)
             {
                 result.HasError = true;
                 result.Message = string.Format(ErrorMessages.DuplicateTenantName, newTenant.Name);
                 return result;
             }
 
+            var tenant = _mapper.Map<Tenant>(newTenant);
+            _context.Tenants.Add(tenant);
+
+            await _context.SaveChangesAsync();
+         
             result.Data = _mapper.Map<TenantPreviewDto>(tenant);
 
             return result;