hehe, guess there is 1 problem with this solution. mysql doesn't do xor. but found a ref saying "a XOR b is mathematically equal to (a AND (NOT b)) OR ((NOT a) and b)"
On Thursday 19 June 2003 09:51, Matthew Smith wrote: > Hi, > > If you convert the IP address into integers, then do an xor (exclusive or), > you could call the resultant value the approximate 'distance' between the > values. > > (think of the IP address in binary, any identical bits will result in 0, > any differing will be 1. This means that the most significant '1' will be > the first dissimilar bit between the two IP addresses. This is really what > you are after. However, including any lesser significant bits may well be > OK for your application.) > > OK, so how in SQL > > You need to create, on the fly > > ipAddress1 ^ ipAddress2 > > (order does not matter) where they are both integers (mysql will use 64bit > integer arithmetic). > > You just need to ORDER BY this value. > > > > > > Regards > > > Matthew > > > -----Original Message----- > From: Ray [mailto:[EMAIL PROTECTED] > Sent: 19 June 2003 15:33 > To: [EMAIL PROTECTED] > Subject: wierd sort query, how do you do it? (sort by ip proximity > guess) > > > currently i have a table with an ip coloumn in text 123.45.67.89 > though it shouldn't be a big deal to convert it to binary, but was > wondering if there is an easy way to sort by closeness to a given ip > address? > > ie records that come out sorted as > same class sub-c > same class c > same class c > same class b > same class a > other addresses > other addresses > > the only thing i can think of at this point is a really long > order by <if same c>,<if same b>,<if same a> -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe: http://lists.mysql.com/[EMAIL PROTECTED]
