title: Integer PadLeft function in T-SQL
body: <p>I have the following table A:</p>
  
  <pre><code>id
  ----
  1
  2
  12
  123
  1234
  </code></pre>
  
  <p>I need to left-pad the <code>id</code> values with zero's:</p>
  
  <pre><code>id
  ----
  0001
  0002
  0012
  0123
  1234
  </code></pre>
  
  <p>How can I achieve this?</p>