//************************* For Assign *******************
public string AssignCourse(CourseAssignTeacher courseAssignTeacher)
{
if (courseAssignGateway.IsCourseExists(courseAssignTeacher.CourseId))
{
return("This Course already has been taken");
}
else
{
int rowAffect = courseAssignGateway.AssignCourse(courseAssignTeacher);
if (rowAffect > 0)
{
return("Assign Successful");
}
else
{
return("Assign Failed");
}
}
}