Models.cs

using System.ComponentModel.DataAnnotations.Schema;

[Table("TPTUsers")]
public class TPTUser
{
    public int Id { get; set; }
    public string Username { get; set; }
    public string Email { get; set; }
}

[Table("TPTTeachers")]
public class TPTTeacher : TPTUser
{
    public string Designation { get; set; }
    public string Speciality { get; set; }
}

[Table("TPTStudents")]
public class TPTStudent : TPTUser
{
    public string CGPA { get; set; }
    public string Major { get; set; }
}