分组后加条件HAVING使用方法

SELECT C.ipsegment,D.ipsegment_scan_num FROM ddos_network_ipstatus AS A
INNER JOIN common_idc_ip AS B ON A.ip_id = B.id
INNER JOIN common_idc_ipsegment AS C ON  B.ipsegment_id = C.id
INNER JOIN ddos_ploy_scan AS D on C.id = D.ipsegment_id
WHERE
    UNIX_TIMESTAMP(now()) - UNIX_TIMESTAMP(A.ip_block_time) < D.ipsegment_scan_limit
GROUP BY C.id HAVING count(A.id) >= D.ipsegment_scan_num