SQL Server: Finding Nearest Location - sql-server

Question

Given the following SQL which returns a list of airports based on a given city, how would I further enhance it to sort the results by what's nearest to me? It seems like it should be simple enough but it eludes me.
DECLARE #latRange float
DECLARE #LongRange float
DECLARE #LowLatitude float
DECLARE #HighLatitude float
DECLARE #LowLongitude float
DECLARE #HighLongitude float
DECLARE #Radius float = 100
DECLARE #istartlat float
DECLARE #istartlong float
Select #istartlat=Latitude, #istartlong=Longitude from Lookup where PlaceName = '"Franklin"' and StateCode = '"AR"'
Select #latRange = #Radius / ((6076 / 5280) * 60)
Select #LongRange = #Radius / (((COS((#istartlat * 3.14592653589 / 180)) * 6076.) / 5280. * 60))
Select #LowLatitude = #istartlat - #latRange
Select #HighLatitude = #istartlat + #latRange
Select #LowLongitude = #istartlong - #LongRange
Select #HighLongitude = #istartlong + #LongRange
Select a.City, a.State, a.AirportCode, a.AirportName, a.CountryCode
from PFM_Airport a
where (a.Latitude <= #HighLatitude) and (a.Latitude >= #LowLatitude) and (a.Longitude >= #LowLongitude)
and (a.Longitude <= #HighLongitude)
--and a.CountryCode in ('USA', 'CANADA')
order by a.Latitude, a.Longitude;

Answer 1

#hatchet is right.. Assuming your instance of SQL Server support geography spatial data then you should consider using that data type for the calculations, you also may find useful some of this code, just replace the table names, conditionals and pagination as needed:
ALTER PROCEDURE [dbo].[SP_NearestPOIReloaded]
(
-- Add the parameters for the stored procedure here
#LAT float,
#LNG float,
#DISTANCE int,
#CURRENTPAGE Int,
#PAGESIZE Int,
#COUNT int OUTPUT
)
AS
BEGIN
-- SET NOCOUNT ON added to prevent extra result sets from
-- interfering with SELECT statements.
SET NOCOUNT ON;
/*for pagination*/
SET #COUNT = (SELECT COUNT(*) FROM dbo.Lugares as [L] WHERE dbo.DistanceBetween(#LAT, #LNG, [L].lat, [L].lng) < #DISTANCE)
/*paginated resultset*/
SELECT * FROM (
SELECT ROW_NUMBER()Over(Order by dbo.DistanceBetween(#LAT, #LNG, [L].lat, [L].lng) Asc) As [RowNum], dbo.DistanceBetween(#LAT, #LNG, [L].lat, [L].lng) as [distance], [L].*, [E].name as [empresaName], [U].userName as [userName]
FROM dbo.Lugares as [L], dbo.Empresas as [E], dbo.Usuarios as [U]
WHERE dbo.DistanceBetween(#LAT, #LNG, [L].lat, [L].lng) < #DISTANCE AND
[L].usuarioId = [U].id AND [L].empresaId = [E].id
)
AS ResultadoPaginado
WHERE RowNum BETWEEN (#CURRENTPAGE - 1) * #PAGESIZE + 1 AND #CURRENTPAGE * #PAGESIZE
END
this depends on a function called DistanceBetween (if your instance does not support spacial data type, then this is the part you must replace with a variation of your own code):
ALTER FUNCTION [dbo].[DistanceBetween]
(
-- Add the parameters for the function here
#PIVOTE_LAT as float,
#PIVOTE_LNG as float,
#LAT as float,
#LNG as float
)
returns real
as begin
declare #distance real;
declare #PIVOTE_POINT geography = geography::Point(#PIVOTE_LAT,#PIVOTE_LNG, 4326);
declare #POINT geography = geography::Point(#LAT,#LNG, 4326);
set #distance = #PIVOTE_POINT.STDistance(#POINT);
return (#distance);
end

Answer 2

how would I further enhance it to sort the results by what's nearest to me?
I believe that in SQL Server 2000, to sort on a calculated value you must either duplicate the calculation in the ORDER BY clause ORDER BY < the calculation> or you can do this:
select FOO.a, FOO.b, FOO.myvalue
from
(
select a, b, <some calculation> as myvalue
from T
where <some calculation> <= {some value}
) as FOO
order by FOO.myvalue
P.S. But in later versions of SQL you can sort on a column alias.
In any case, you must have a column to contain the calculated distance.