title: Insert number of blank rows in SQL
body: <p>Using a SQL query, I need to include blank rows in the result to make every group of <code>(family_id)</code> equal to 4 rows</p>
  
  <pre><code>SELECT   
      ROW_NUMBER() OVER(PARTITION BY family_id ORDER BY family_id) AS rowNum,
      full_name as name, family_id
  FROM
      tbl_person
  </code></pre>
  
  <p>Like this:</p>
  
  <p><a href="https://i.stack.imgur.com/d6QMe.jpg" rel="nofollow"><img src="https://i.stack.imgur.com/d6QMe.jpg" alt="original result"></a></p>
  
  <p>and the result will be</p>
  
  <p><a href="https://i.stack.imgur.com/f5v5v.jpg" rel="nofollow"><img src="https://i.stack.imgur.com/f5v5v.jpg" alt="enter image description here"></a></p>