title: How to turn off auto_increment in Rails Active Record
body: <p>Is it possible to create primary key without <code>auto_increment</code> flag in <strong>ActiveRecord</strong>?</p>
  
  <p>I can't do </p>
  
  <pre><code>create table :blah, :id =&gt; false
  </code></pre>
  
  <p>because I want to have primary key index on the column. I looked up <a href="http://ar.rubyonrails.org/" rel="noreferrer">documentation</a> but didn't find anything useful.</p>
  
  <p><strong>Is it possible to create primary key without auto_increment?</strong></p>