title: Tables Hierarchy in a database
body: <p>I am not sure if this is the right forum to ask this question but am assuming it is a technical question so posting here.</p>
  
  <p>It was asked during an interview that;</p>
  
  <p>We have 4 tables.. Country, City, District, Sub District. How to make hierarchy of them in database ( One way is adding foreign reference of parent in child table... but what's the other way?)</p>
  
  <p>I am not able to find any other way but to add all the information in one table but the question was 'how to make <strong>hierarchy</strong> of them' ? which means multiple tables are involved.</p>
  
  <p>Could anyone please suggest what could be the other way?</p>