title: Oracle : sql select query if condition parameter is null then ignore the parameter
body: <p>suppose I have a oracle query    </p>
  
  <pre><code>SELECT *
  FROM EMPLOYEE
  WHERE DEPARTMENT = ?
      AND DESIGNATION = ?
      AND DISTRICT = ?
      AND CIRCLE = ?
  </code></pre>
  
  <p>And quite possible any 1 or 2 or 3 of the parameter (?) can be empty or null.<br>
  so what should I do so that the empty parameters are totally "<em>ignore</em>" in the where clause and only search for the non-empty parameter in the table.<br>
  How can I achieve this</p>
  
  <p>Please help..
  The query must be compatible oracle 10g. Thanks</p>