public Doctor GetDoctocById(int id)
{
if (id < 0)
{
throw new Exception("Input is not valid");
}
try
{
var doctor = _doctorDAO.GetById(id);
if (doctor == null)
{
throw new Exception("Doctor is not existed");
}
return(doctor);
}
catch (Exception e)
{
throw new Exception(e.Message);
}
}