mysql-gomonth month date cal month

DROP VIEW POQTYOS;
create view POQTYOS AS
SELECT POBODY.*,POQTY-GRNQTY AS QTY
, SALES_ORDER_HEAD.QD_NO AS QD_NO
, VENDOR.NAME AS SUPPLIER_NAME
, '' as COMMENT
,'' as REMARK
,'' as SERIAL_NUMBER
,POBODY.PO_MTYPE as MAINTENANCE_TYPE
,CURDATE() as ACTIVE_DATE
,POBODY.PO_MMTHS as MAINTAIN_MTHS
,CURDATE()+INTERVAL POBODY.PO_MMTHS MONTH as EXPIRE_DATE
FROM POBODY
LEFT JOIN VENDOR ON POBODY.SUPPLIER=VENDOR.RECORDID
LEFT JOIN SALES_ORDER_HEAD ON SALES_ORDER_HEAD.RECORDID=POBODY.SALES_ORDER_RECORDID
WHERE POHSTA='A' AND POQTY-GRNQTY # 0
;