title: LIKE with % on column names
body: <p>Here is my query that results in a syntax error:</p>
  
  <pre><code>SELECT * 
  FROM account_invoice,sale_order
  WHERE sale_order.name LIKE %account_invoice.origin%
  </code></pre>
  
  <p>The account_invoice.origin field contains the text of sale_order.name, plus other text as well, so I need to match sale_order.name string anywhere in the account_invoice.origin string.  </p>
  
  <p>I'm using PostgreSQL 8.4.</p>