title: One to many relationship with ensuring at least 1 record exists in (many table)
body: <p>How would you design tables in the following scenerio.</p>
  
  <p>I have two tables in one-to-many relationship. </p>
  
  <pre><code>Table A - One
  Table B - Many
  </code></pre>
  
  <p>Such relation doesn't give me
  on database level the protection that at least 1 record will be present in B table.</p>
  
  <p>Moreover Table A should know the last identifier from Table B (basing on any rule).</p>
  
  <p>How could I accomplish such a task?</p>