title: meaning of %%% in sql query?
body: <p>I am familiar with this kind of query:</p>
  
  <pre><code>select * from tableA where foo like '%bar%'
  </code></pre>
  
  <p>But today I run into three adjacent percentage signs in some legacy code, like this:</p>
  
  <pre><code>select * from tableA where foo like '%%%'
  </code></pre>
  
  <p>This query seems to work, both on mssql and oracle, when foo is of string type (varchar, etc.) but it fails when foo is numeric.</p>
  
  <p>Any idea what it means?</p>
  
  <p>EDIT: sorry about the typo in original question, the query uses the LIKE operator.</p>