SQL 分解IPv4地址

select ip,
to_number(substr(ip, 1, instr(ip, '.', 1, 1)-1)) newip1,
to_number(substr(ip, instr(ip,'.',1,1)+1, instr(ip, '.', 1, 2)-instr(ip,'.',1,1)-1)) newip2,
to_number(substr(ip, instr(ip,'.',1,2)+1, instr(ip, '.', 1, 3)-instr(ip,'.',1,2)-1)) newip3,
to_number(substr(ip, instr(ip,'.',1,3)+1, length(ip)+1-instr(ip,'.',1,3))) newip4
from (select '10.1.2.123' ip from dual)

select regexp_substr(t.ip,'[^.]+',1,1),
regexp_substr(t.ip,'[^.]+',1,2),
regexp_substr(t.ip,'[^.]+',1,3),
regexp_substr(t.ip,'[^.]+',1,4) from
(select '10.1.2.123' ip from dual)  t