"Bas Scheffers" <[EMAIL PROTECTED]> writes: > Once you have that, the rest is easy. create a column of the type "point" > and store the grid coordinates in there. The just use the "contains" > operator (~) in a query. > (http://www.postgresql.org/docs/7.4/static/functions-geometry.html)
> Example: > My coordinates are 523857,175349. So to find anyone living within 10KM of > me, I just do "select * from people where '((523857,175349),10000)' ~ > location" > Unfortunately, Postgres doesn't know how to index this. You can index such queries using rtree indexes. There was a discussion of this with a full example just a couple weeks ago: http://archives.postgresql.org/pgsql-novice/2004-03/msg00070.php It's likely that PostGIS provides an even better solution, but I haven't used it. regards, tom lane ---------------------------(end of broadcast)--------------------------- TIP 2: you can get off all lists at once with the unregister command (send "unregister YourEmailAddressHere" to [EMAIL PROTECTED])
