title: MySql/PHP - Designing my first database. Need reviews
body: <p>I'm designing my first database and writing my first PHP project from scratch and I need someone to review database scheme.</p>
  
  <p><strong>Purpose of PHP script:</strong> To display traffic statistic for various sites in my network when I publish promotional videos on sites like Youtube, Myspace, Metacafe, Vimeo etc.</p>
  
  <p><strong>How I plan to organize it:</strong></p>
  
  <ol>
  <li>One site can have multiple categories like "guitar lessons",
  "singing lessons", "dancing lessons".</li>
  <li>Some categories can have subcategories. Like "guitar lessons" can be split to "bass" and "electric"</li>
  <li>In one category can be one promotional video. On image below, video is named <strong><em>item</em></strong>.</li>
  <li>One item (promotional video) can be created in only one category </li>
  <li>One promotional video can be submitted to multiple video sharing sites (Youtube, Vimeo etc..)</li>
  <li>One promotional video can have several different meta data like "title" and "description"</li>
  </ol>
  
  <p><strong>Scenarios that can happen:</strong></p>
  
  <ol start="8">
  <li>Maybe someday Youtube will delete one of my promotional video, in
  that case I would reupload it again with probably different "title"
  and "description", but I would like to show some old info in
  statistic like previous number of views before deletion.</li>
  <li>I can't think any other right now..</li>
  </ol>
  
  <p>EDIT:
  <strong>I have added table itemStats</strong>
  <img src="https://i.stack.imgur.com/VwAGl.png" alt="enter image description here"></p>
  
  <p><strong>EDIT2: I'm not sure if I'm going to need separate itemStats table. I'm thinking to join it with itemMeta?</strong></p>