title: oracle sql developer ora-00904 stored procedure execution error
body: <p>I have wrote simple stored procedure in Oracle SQL Developer but found, attached ,error on execution/run step. </p>
  
  <p><img src="https://i.stack.imgur.com/MHCaI.png" alt="problem faced"></p>
  
  <p>Here is my code:</p>
  
  <pre><code>CREATE OR REPLACE PROCEDURE EMP_NAME (EMP_ID_IN      IN     VARCHAR2,
                                        EMP_NAME_OUT      OUT VARCHAR2)
  AS
  BEGIN
     SELECT first_name
       INTO EMP_NAME_OUT
       FROM employee
      WHERE emp_id = EMP_ID_IN;
  END EMP_NAME;
  </code></pre>
  
  <p>It also shows this error </p>
  
  <p><img src="https://i.stack.imgur.com/WdhzH.png" alt="error_log"></p>