Table person {
  id int PK
  name varchar
  parent_id int
}

Table club {
  id int PK
  person_id int
  class_id int
  name varchar
}

Table team {
  id int PK
  club_id int
  children_id int
  num_of_children int
  name varchar
}


Ref: person.id < club.person_id
Ref: club.id < team.club_id
Ref: team.children_id < person.id
Ref: person.parent_id > person.id