public List <CourseOverview> GetCourseOverview() { var courseEntries = _courseService.GetCourses(); List <CourseOverview> overviews = new List <CourseOverview>(); foreach (var course in courseEntries) { overviews.Add(new CourseOverview { Course = _mapper.Map <Course, CourseDTO>(course), TeachersCount = _teacherService.GetTeachersBy(course.Id).Count(), StudentsCount = _studentService.SearchStudentsBy(course.Id).Count(), AverageGrade = String.Format("{0:0.0#}", _gradeService.GetAverageByCourse(course.Id)) }); } return(overviews); }