TO_CHAR(ADD_MONTHS(SYSDATE,-1),'YYYY'),TO_CHAR(ADD_MONTHS(SYSDATE,-1),'MM')
TO_CHAR(ADD_MONTHS(SYSDATE,0),'YYYY'),TO_CHAR(ADD_MONTHS(SYSDATE,0),'MM')
TO_DATE('20151231','YYYY-MM-DD') - TO_DATE(ERSDA,'YYYY-MM-DD')
转载于:https://www.cnblogs.com/Dream-Lasting/p/8991070.html