title: Delete attribute from model in Ruby on Rails
body: <p>I generated a User model using this command:</p>
  
  <pre><code>rails generate model User name:string date_birth:date age:int...
  </code></pre>
  
  <p>As you can see I made a mistake. I entered a date of birth and an age. Now I also migrated into a mySql database. Is there any way to just delete the age field?</p>
  
  <p>Edit: Is it also possible to add a field?</p>