title: sql, cout number of childrens per each campaigns ancestry
body: <p>how to count in sql number of children per name in ancestry like tree structure</p>
  
  <pre><code>ID | NAME                    | PATH
  100 | Electronics &amp; Computers | /100
  101 | Games                   | /100/101
  102 | Xbox360                 | /100/101/102
  103 | PS4                     | /100/101/103
  </code></pre>
  
  <p>so i should have something like</p>
  
  <pre><code>100 | 3
  101 | 2
  102 | 0
  103 | 0
  </code></pre>
  
  <p>thanks much for help</p>