Why not just do: SELECT zipcode, zipdist($lat1d,$lon1d,lat,long) as distance from zipcodes where zipdist($lat1d,$lon1d,lat,long) <= $dist;";
On Mon, 2005-04-11 at 20:25, Bill Lawrence wrote: > Boy I sure thought that would work... I received the following from postgres: > > ERROR: Attribute "distance" not found. > > Started looking into gist.... Looks complex. > > Any other ideas? > > > -----Original Message----- > From: PFC [mailto:[EMAIL PROTECTED] > Sent: Monday, April 11, 2005 1:51 AM > To: Bill Lawrence; pgsql-sql@postgresql.org > Subject: Re: [SQL] Getting the output of a function used in a where clause > > > try: > > SELECT zipcode, zipdist($lat1d,$lon1d,lat,long) as distance from zipcodes > where distance <= $dist;"; > > OR you could use a gist index with a geometric datatype to get it a lot > faster. > > > On Sat, 09 Apr 2005 03:43:39 +0200, Bill Lawrence <[EMAIL PROTECTED]> > wrote: > > > HI, > > > > I'm a newbie so please bear with me. I have a function defined (got it > > from > > one of your threads... thanks Joe Conway) which calculates the distance > > between 2 zip code centeroids (in lat,long). This thing works great. > > However, I want to sort my results by distance without incurring the > > additional burden of executing the function twice. A simplified version > > of > > my current SQL (written in a perl cgi) that returns a set of zip codes > > within a given radius is: > > > > > > What I want to write is something like: > > > > $sql = "SELECT zipcode, distance from zipcodes where distance <= $dist > > order > > by distance;"; > > > > But I don't the magic SQL phrase to populate the distance variable using > > my > > nifty function. Do I need to create an output type for distance? > > > > Thanks in advance! > > > > Bill > > > > > > > > > > > ---------------------------(end of broadcast)--------------------------- > TIP 7: don't forget to increase your free space map settings ---------------------------(end of broadcast)--------------------------- TIP 9: the planner will ignore your desire to choose an index scan if your joining column's datatypes do not match
