title: Checking whether a string contains a certain character
body: <p>I'm constructing a transport related site and want to check whether a service operates on a certain day. I have column called "operating_days" in my database with "1234567", "12345", "67" etc as entries with 1 indicating Monday, 2 indicating Tuesday and so on. </p>
  
  <p>A query like below would be helpful but of course with a working command to check the string.</p>
  
  <pre><code>$operating_query = "SELECT departure_point FROM services WHERE operating_days LIKE '3' AND trip_number LIKE '" . $_SESSION['book_trip_number'] . "'";
  </code></pre>
  
  <p>Many thanks.</p>