title: Creating a package
body: <p>I am trying to Create a package MSGG_SESSION with a procedure authenticate that accepts two VARCHAR2
  parameters for username and password. Put an package-private NUMBER variable for the
  current person ID. If “authenticate” matches a username and password in MSGG_USER , put the
  matching PERSON_ID in the new variable. when i put this into oracle sql developer i get and error. i already created a table MSGG_SESSION  and a MSGG_USER table already exists. (PRIV-NUMBER is my package private number variable for the current person ID) </p>
  
  <pre><code>CREATE OR REPLACE PACKAGE MSGG_SESSION
  IS
  
      PROCEDURE AUTHENTICATE (USERNAME IN VARCHAR2, PASSWORD IN VARCHAR2);
      FUNCTION AUTHENTICATED_USER RETURN VARCHAR2;
  END MSGG_SESSION;
  /
  
  CREATE OR REPLACE PACKAGE BODY MSGG_SESSION
  IS
      PRIV_NUMBER VARCHAR2(100);
  
      PROCEDURE AUTHENTICATE (USERNAME_TO_AUTH IN VARCHAR2, PASSWORD_TO_USE IN VARCHAR2)
      IS
      BEGIN
          PRIV_NUMBER := NULL;
          SELECT USERNAME
              INTO PRIV_NUMBER
          FROM
              USER_PASSWORD
          WHERE
              lower(username) = lower(username_to_auth) and password = password_to_use;
      exception
          when NO_DATA_FOUND then
              raise NOT_AUTHENTICATED;
          when others then
              raise;
      END AUTHENTICATE;
  
      FUNCTION GET_USER_ID
      RETURN VARCHAR2
      is
      begin
          return priv_number;
      end get_user_id;
  
  END MSGG_SESSION;
  /
  </code></pre>