Table users { 

   id int [pk]

   name text

   email text [unique]

   created_at timestamp

   updated_at timestamp

}

Table courses {

   id int [pk]

   title text

   credits int

   created_at timestamp

   updated_at timestamp

}

Table enrollments {

   id int [pk]

   student_id int [ref: > users.id]

   course_id int [ref: > courses.id]

   enrollment_date text

   created_at timestamp

   updated_at timestamp

}