$ cat sql/insertBatchCode.sql
DROP PROCEDURE IF EXISTS insertBatchCode;
DELIMITER //
CREATE PROCEDURE insertBatchCode(id INT(10))
BEGIN
  DECLARE mfgDate DATE;
  DECLARE batchCode CHAR(8);
  SELECT date_manufactured FROM batch WHERE batchid=id
    INTO mfgDate;
  CALL getBatchCode(mfgDate, batchCode);
  UPDATE batch SET batchcode=batchCode WHERE batchid=id;
END;
//
DELIMITER ;