title: MySQL one column equal another?
body: <p>How in php/mySQL can i make a column equal another column?</p>
  
  <p>id is auto increment, xid should be unique. Can i make xid = id in SQL? (the reason for this is to log changes but i'll explain more if needed)</p>
  
  <p>To make xid unique the best way is to copy the auto increment of id</p>
  
  <pre><code>+----+-----+----------+----------------+------+---------+
  | id | xid | title    | body           | page | visible |
  +----+-----+----------+----------------+------+---------+
  |  1 |  1  | my title | my body        | NULL |       1 | 
  |  2 |  2  | my title | my body edited |    1 |       0 | 
  +----+-----+----------+----------------+------+---------+
  
  $queryX = "INSERT INTO table (xid, title, body, page, visible) 
  VALUES (, 'Plays', 'it's playing', 'book page', 1)";
  </code></pre>