title: SQL generate new rows
body: <p>I have a following table:</p>
  
  <pre><code>ShopId  NumberOfOrders
  1       2
  2       3
  3       2
  4       0
  </code></pre>
  
  <p>Example result:</p>
  
  <pre><code>ShopId   OrderId
  1        NULL
  1        NULL
  2        NULL
  2        NULL
  2        NULL
  3        NULL
  3        NULL
  </code></pre>
  
  <p>How to make a query that returns x number of rows for each Shop where x depends on NumberOfOrders?</p>