title: Rails Migration to convert string to integer?
body: <p>Is it possible to change a field that's a string to an integer without clearing the data already entered?</p>
  
  <p>The current db structure for the table in question is:</p>
  
  <pre><code>create_table :people do |t|
  t.string :company_id
  </code></pre>
  
  <p>Is this possible using migrations?</p>
  
  <p>I'm thinking maybe in the migration drop the old field, create a new one that's an integer - but I'm worried this will clear all of the data already entered.</p>
  
  <p>Thanks,</p>
  
  <p>Danny</p>