title: PHP MySQL INSERT ON DUPLICATE KEY UPDATE not working
body: <p>My query:</p>
  
  <pre><code>INSERT INTO `table` (`article_id`, `score_count`) VALUES (1922, '{\"1\":3,\"2\":2,\"3\":10,\"4\":2,\"5\":1}') ON DUPLICATE KEY UPDATE `article_id`= 1922
  </code></pre>
  
  <p>And my article_id column is set as primary unique key. After I run this I get 0 rows inserted and no update.</p>