如何从 PostgreSQL 中的两个 IP 获取 CIDR？

Question

在 PostgreSQL 中，我可以获得 CIDR 范围的上下边界，如下所示。

但是如何从两个 IP 地址（通过 SQL）获取 CIDR？
例如

输入“192.168.0.0”；“192.168.255.255”
输出“192.168.0.0/16”

SELECT 
     network
    ,network::cidr 
    -- http://technobytz.com/ip-address-data-types-postgresql.html
    --,netmask(network::cidr) AS nm  
    --,~netmask(network::cidr) AS nnm
    ,host(network::cidr) AS lower 
    ,host(broadcast(network::cidr)) AS upper -- broadcast: last address in the range
    ,family(network::cidr) as fam  -- IPv4, IPv6
    ,masklen(network::cidr) as masklen
FROM 
(
          SELECT CAST('192.168.1.1/32' AS varchar(100)) as network 
    UNION SELECT CAST('192.168.0.0/16' AS varchar(100)) as network 
    --UNION SELECT CAST('192.168.0.1/16' AS varchar(100)) as network 

) AS tempT

Answer 1

我认为您正在寻找inet_merge：

test=> SELECT inet_merge('192.168.0.0', '192.168.128.255');
??????????????????
?   inet_merge   ?
??????????????????
? 192.168.0.0/16 ?
??????????????????
(1 row)