pl/sql procedure
CREATE OR REPLACE PROCEDURE print_contact(
    in_customer_id NUMBER 
)
IS
  r_contact contacts%ROWTYPE;
BEGIN
  -- get contact based on customer id
  SELECT *
  INTO r_contact
  FROM contacts
  WHERE customer_id = p_customer_id;
  -- print out contact's information
  dbms_output.put_line( r_contact.first_name || ' ' ||
  r_contact.last_name || '<' || r_contact.email ||'>' );
EXCEPTION
   WHEN OTHERS THEN
      dbms_output.put_line( SQLERRM );
END;
