title: What the difference between mysql and ruby-mysql gem
body: <p>I'm trying to install <code>mysql</code> or <code>mysql2</code> gem but it's not working.</p>
  
  <p>I have already installed <code>ruby-mysql</code>.</p>
  
  <p>Does this gem have the same features as the <code>mysql2</code> gem?</p>