public IActionResult CreateTeaches(string cid, string iid, string semester)
{
//check if primary key is already exists
var cidkey = _gradeDbContext.Teaches.FirstOrDefault(i => i.CourseId.Equals(cid, System.StringComparison.InvariantCultureIgnoreCase));
var courseKey = _gradeDbContext.Course.FirstOrDefault(i => i.CourseId.Equals(cid, System.StringComparison.InvariantCultureIgnoreCase));
var instKey = _gradeDbContext.Instructor.FirstOrDefault(i => i.InstructorId.Equals(iid, System.StringComparison.InvariantCultureIgnoreCase));
//We need the courseid NOT TO BE in teaches table --> cidkey
//We need the courseid to BE in course table --> courseKeyz
//We need the instructorId to be in instr table --> instKey
if (cidkey == null && courseKey != null && instKey != null)
{
_gradeDbContext.Add(new TeachesModel
{
CourseId = cid,
InstructorId = iid,
Semester = semester
});
_gradeDbContext.SaveChanges();
_gradeDbContext.Dispose();
return(RedirectToAction("Index"));
}
else
{
return(BadRequest($"Cannot insert teaches:{cid} already exists, instructor id {iid} or course id {cid} is not created!"));
}
}
public IActionResult CreateCourse(string id, string title, ushort hours)
{
//check if primary key is already exists
var key = _gradeDbContext.Course.FirstOrDefault(i => i.CourseId.Equals(id, System.StringComparison.InvariantCultureIgnoreCase));
if (key == null)
{
_gradeDbContext.Add(new CourseModel
{
CourseId = id,
Title = title,
CreditHours = hours
});
_gradeDbContext.SaveChanges();
_gradeDbContext.Dispose();
return(RedirectToAction("Index"));
}
else
{
return(BadRequest($"Cannot insert course: {id} already exists"));
}
}
public IActionResult CreateInstructor(string id, string name, string department)
{
//check if primary key is already exists
var key = _gradeDbContext.Instructor.FirstOrDefault(i => i.InstructorId.Equals(id, System.StringComparison.InvariantCultureIgnoreCase));
if (key == null)
{
_gradeDbContext.Add(new InstructorModel
{
InstructorId = id,
InstructorName = name,
Department = department
});
_gradeDbContext.SaveChanges();
_gradeDbContext.Dispose();
return(RedirectToAction("Index"));
}
else
{
return(BadRequest($"Cannot insert instructor: {id} already exists"));
}
}