Sqlserver 计算两坐标距离函数

if exists (select * from dbo.sysobjects where id = object_id(N‘UF_ETL_GetDistance‘) and xtype in (N‘FN‘, N‘IF‘, N‘TF‘))
    drop function UF_ETL_GetDistance
GO

CREATE FUNCTION UF_ETL_GetDistance
( 
   @sLng    DECIMAL(12,6),
   @sLat    DECIMAL(12,6),
   @eLng    DECIMAL(12,6),
   @eLat    DECIMAL(12,6)
)
RETURNS DECIMAL(12,4)
AS
BEGIN
   DECLARE @result DECIMAL(12,4)
   SELECT @result = 6378137.0*ACOS(SIN(@sLat/180*PI())*SIN(@eLat/180*PI())+COS(@sLat/180*PI())*COS(@eLat/180*PI())*COS((@sLng-@eLng)/180*PI()))
   RETURN @result/1000
END
go