MySQL左连接同一列上的多个列

Question

基本上我要完成的，是我想要的test.zfirewallaudit.src_ip和test.zfirewallaudit.dst_ip场加入的inventory.dns_zones.ip列，所以我基本上可以有一个准确的主机名（ inventory.dns_zones.subdomain ）for test.zfirewallaudit.src_ip和test.zfirewallaudit.dst_ip 。 所以基本上我想要一列src_ip子域和dst_ip子域。

SELECT test.zfirewallaudit.src_ip, 
test.zfirewallaudit.src_zone, 
test.zfirewallaudit.dst_ip, 
test.zfirewallaudit.dst_zone, 
test.zfirewallaudit.dst_port, 
test.zfirewallaudit.rulename, 
test.zfirewallaudit.application,
inventory.dns_zones.subdomain
FROM test.zfirewallaudit LEFT JOIN inventory.dns_zones ON zfirewallaudit.src_ip = inventory.dns_zones.ip OR zfirewallaudit.dst_ip = inventory.dns_zones.ip LIMIT 10;

问题是，我需要的inventory.dns_zones.subdomain为两个test.zfirewallaudit.src_ip和...dst_ip值。 当前查询只给我1 subdomain列

Answer 1

你需要加入对inventory.dns_zones两次，一次用于src和一次针对DST：

SELECT test.zfirewallaudit.src_ip, 
test.zfirewallaudit.src_zone, 
test.zfirewallaudit.dst_ip, 
test.zfirewallaudit.dst_zone, 
test.zfirewallaudit.dst_port, 
test.zfirewallaudit.rulename, 
test.zfirewallaudit.application,
dns_zones_src.subdomain,
dns_zones_dst.subdomain
FROM test.zfirewallaudit
LEFT JOIN inventory.dns_zones AS dns_zones_src ON ( zfirewallaudit.src_ip = dns_zones_src.ip )
LEFT JOIN inventory.dns_zones AS dns_zones_dst ON ( zfirewallaudit.dst_ip = dns_zones_dst.ip )
LIMIT 10;