Since you're using SQL Server 2008, you have the geography
data type available, which is designed for exactly this kind of data:
DECLARE @source geography = 'POINT(0 51.5)'
DECLARE @target geography = 'POINT(-3 56)'
SELECT @source.STDistance(@target)
Gives
----------------------
538404.100197555
(1 row(s) affected)
Telling us it is about 538 km from (near) London to (near) Edinburgh.
Naturally there will be an amount of learning to do first, but once you know it it's far far easier than implementing your own Haversine calculation; plus you get a LOT of functionality.
If you want to retain your existing data structure, you can still use STDistance
, by constructing suitable geography
instances using the Point
method:
DECLARE @orig_lat DECIMAL(12, 9)
DECLARE @orig_lng DECIMAL(12, 9)
SET @orig_lat=53.381538 set @orig_lng=-1.463526
DECLARE @orig geography = geography::Point(@orig_lat, @orig_lng, 4326);
SELECT *,
@orig.STDistance(geography::Point(dest.Latitude, dest.Longitude, 4326))
AS distance
--INTO #includeDistances
FROM #orig dest
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