Question

I’m working with an application that has the following tables for storing IP address ranges:

IP_RANGE
--------
RANGE_ID      primary key
NETWORK_ID    foreign key into NETWORK table (not described here)
IP_ID         foreign key into IP_ADDRESS table
RANGE_TYPE    varchar, values "START" or "END"

IP_ADDRESS
----
IP_ID         primary key
IP_NETWORK    number (decimal representation of network portion of address)
IP_INTERFACE  number (decimal representation of interface portion of address)

A given IP address range is represented by two rows in the IP_RANGE table: one with a RANGE_TYPE value of “START” and another with a value of “END”, both of which have the same value for NETWORK_ID. Each of these rows also point to a row in the IP_ADDRESS table which stores the actual addresses.

I need to write a SELECT statement that gives me all of the NETWORK_IDs which have IP ranges that have any addresses in common with a given arbitrary IP range.

I know how to inspect the IP_ADDRESS table to find individual addresses that fall inside or outside my desired range, but I don’t know how to restrict my search to only begin/end pairs that have the same NETWORK_ID.

(I suppose this is really a pure SQL question rather than anything specifically to do with IP addresses.)

Oracle Database 11g Enterprise Edition Release 11.1.0.7.0 – 64bit Production

Answer 1

You need to join IP_RANGE to itself to get information about both the range-start and the range-end with a single query. You also need to join each occurrence of IP_RANGE to IP_ADDRESS in order to do your IP-address comparisons; so, all told, you’ll have something like this:

SELECT ip_range_start.network_id
  FROM ip_range ip_range_start
  JOIN ip_address ip_range_start_address
    ON ip_range_start.ip_id = ip_range_start_address.ip_id
  JOIN ip_range ip_range_end
    ON ip_range_start.network_id = ip_range_end.network_id
  JOIN ip_address ip_range_end_address
    ON ip_range_end.ip_id = ip_range_end_address.ip_id
 WHERE ip_range_start.range_type = 'START'
   AND ip_range_end.range_type = 'END'
   AND (    ... -- ip_range_start_address less than or equal to end of desired IP range
         OR ... -- ip_range_end_address greater than or equal to start of desired IP range
       )
;