CREATE FUNCTION [dbo].[GetDistance](@LatBegin decimal(11,8), @LngBegin decimal(11,8), @LatEnd decimal(11,8), @LngEnd decimal(11,8)) RETURNS int  
  AS  
BEGIN  
  --距离(米)  
  DECLARE @Distance REAL  
  DECLARE @EARTH_RADIUS REAL  
  SET @EARTH_RADIUS = 6378.137    
  DECLARE @RadLatBegin REAL,@RadLatEnd REAL,@RadLatDiff REAL,@RadLngDiff REAL  
  SET @RadLatBegin = @LatBegin *PI()/180.0    
  SET @RadLatEnd = @LatEnd *PI()/180.0    
  SET @RadLatDiff = @RadLatBegin - @RadLatEnd    
  SET @RadLngDiff = @LngBegin *PI()/180.0 - @LngEnd *PI()/180.0     
  SET @Distance = 2 *ASIN(SQRT(POWER(SIN(@RadLatDiff/2), 2)+COS(@RadLatBegin)*COS(@RadLatEnd)*POWER(SIN(@RadLngDiff/2), 2)))  
  SET @Distance = @Distance * @EARTH_RADIUS  * 1000  
  --SET @Distance = Round(@Distance * 10000) / 10000    
  RETURN @Distance  
END  
GO

使用:

select dbo.GetDistance(1,1,2,2)