我需要找到两个数组之间的公共(public)元素。我的代码是:$sql="SELECTDISTINCTfk_paytbl_discounts_discountidasdiscountidfrompaytbl_discounts_studentsWHEREfk_vtiger_cf_601='".$categoryid."'";$discountstudentinfo=$objdb->customQuery($sql,false);$sql1="SELECTDISTINCTfk_paytbl_discounts_discountidasdiscountidfrompaytbl_discou