title: PHP PDO WHERE field = json?
body: <p><strong>Hello.</strong></p>
  
  <p>So I'm doing the article submission atm and I need articles to have multiple categories... Article categories would be stored in <code>articles</code> table under <code>categories</code> field like this <code>{"cat1","cat2","cat3"}</code>.  But a mind popped to my head... "What if I want to lookup articles by a category?". If I would do something like <code>SELECT * FROM articles WHERE categories = ?</code> then I can't define what categories which post has... So I can't lookup by a  category this way. Any suggestions, solutions? Much appreaciated!</p>
  
  <p><strong>Edit:</strong> If I would retrieve all post from database and do some for each solution it would cause server loads or even crashes for several minutes. Right now I have <strong>7,307</strong> articles.</p>