title: MySQL 'user_id' in where clause is ambiguous problem
body: <p>How can I correct the problem I keep getting from the code below which states <code>'user_id' in where clause is ambiguous</code>. Thanks for the help in advance.</p>
  <p>Here is the mysql table.</p>
  <pre><code>SELECT user.*, user_info.* 
  FROM user 
  INNER JOIN user_info ON user.user_id = user_info.user_id
  WHERE user_id=1
  </code></pre>