I have 2 stored procedures Proc_parent & proc_child.

From Proc_parent procedure I have to call child procedure. if child_proc fails then I have to fail the Proc_parent procedure too.

I am very new learner of it. I have written below procedure

CREATE or replace PROCEDURE "CCDBLOD"."PROC_PARENT" ( ) 
BEGIN  
  INSERT INTO CCDBLOD.TEST VALUES('1','parent_insert');
  CALL CCDBLOD.PROC_CHILD('from_param_insert'); 
  ROLLBACK;
END;

PROC_CHILD:

CREATE PROCEDURE "CCDBLOD"."PROC_CHILD" ( IN "PARAMETER1" VARCHAR(1024) ) 
BEGIN
  DECLARE v_PARAM VARCHAR(30); 
  DECLARE O_V_OUT VARCHAR(30); 
DECLARE SQLSTATE CHAR(5) DEFAULT '00000';

  DECLARE EXIT HANDLER FOR SQLEXCEPTION  
   SET O_V_OUT = SQLSTATE; 
   SET v_PARAM=PARAMETER1; 

 IF v_PARAM = '0' THEN
    SIGNAL SQLSTATE '88888'
    SET MESSAGE_TEXT ='INCORRECT EMPLOYEE_ID';
    INSERT INTO CCDBLOD.TEST VALUES('9','Exception'); 
    COMMIT;
    RETURN;
  END IF;    
  INSERT  INTO CCDBLOD.TEST VALUES('4',v_PARAM);
END;

How do I handle & throw exception in this case? I know how to do this in Java but unfortunately this is my first stored procedure. Please provide me relevant tutorial solution so that I can learn how to handle exception handling.