title: In MySQL how do I use a user defined variable in a WHERE IN clause?
body: <p>I don't understand why this does not work. Can someone explain what I need to do?</p>
  
  <pre><code>SET @my_list = '2,6,8,10,12,13,14,18,19,21';
  
  DELETE FROM my_table WHERE my_table.table_id IN (@my_list);
  </code></pre>