title: how to query get max id from varchar type and the values in numeric?
body: <p>i have table and column id, and the values are 1, 2 ,3,...,10,11,12,13. 
  how to query get max id from varchar type ? i had try </p>
  
  <pre><code>select MAX(id) from table
  </code></pre>
  
  <p>but the result is 9, Please help ??</p>