title: How to add leading zero when number is less than 10?
body: <p>I have a column in my sql table. I am wondering how can I add leading zero to my column when my column's value is less than 10? So for example:</p>
  
  <pre><code>number   result
  1     -&gt;    01
  2     -&gt;    02
  3     -&gt;    03
  4     -&gt;    04
  10    -&gt;    10
  </code></pre>