CREATE OR REPLACE PROCEDURE MAKE_A_CALL
(CALLER_NUM IN VARCHAR2 , RECEIVER_NUM IN VARCHAR2, START_TIME IN VARCHAR2, END_TIME IN VARCHAR2)
IS
V_ID NUMBER ;
V_START TIMESTAMP ;
V_END TIMESTAMP ;
BEGIN

SELECT COUNT(*) INTO V_ID
FROM CALL_DATABASE ;

V_ID := V_ID + 1 ;

V_START := TO_DATE(START_TIME,'yyyy/mm/dd hh24:mi:ss') ;
V_END := TO_DATE(END_TIME,'yyyy/mm/dd hh24:mi:ss') ;

INSERT INTO CALL_DATABASE VALUES(V_ID , CALLER_NUM , RECEIVER_NUM , V_START , V_END) ;

END;
/