如何计算SQL Server中多个点之间的距离？

Question

我有表与GPS数据,如:Latitude,Longitude,Time,UserId

如何聚合指定时间范围内的总距离,按所有点(按时间排序)和用户分组数据对所有距离求和？

谢谢

Answer 1

如果您使用的是SQL Server,则可能对使用地理数据类型感兴趣,因此可以使用专用方法和地理索引来请求数据库.

自SQL Server 2008以来,地理数据类型可用,您可以在此处获得更多信息:

http://msdn.microsoft.com/en-us/library/cc280766.aspx

将数据导入地理列后,您将能够使用STDistance()方法计算两点之间的距离,请参阅MSDN:

http://msdn.microsoft.com/en-us/library/bb933808.aspx

下面是一个示例,其中使用STDistance()来计算以米为单位返回的两个点之间的距离(具有地理变形)(国际标准单位):

DECLARE @pointA geography;
DECLARE @pointB geography;
SET @pointA = geography::STGeomFromText('POINT(-122.34900 50)', 4326);
SET @pointB = geography::STGeomFromText('POINT(-122.34900 47.65100)', 4326);
SELECT @pointA.STDistance(@pointB);

如果您正在使用SQL Server 2005(或者如果您想避免使用地理数据类型),您可以查看CodePlex上的MsSQLSpatial项目,可在此处获取:http://mssqlspatial.codeplex.com/wikipage？title =特点和referringTitle =首页

Answer 2

The below function gives distance between two geocoordinates in miles

create function [dbo].[fnCalcDistanceMiles] (@Lat1 decimal(8,4), @Long1 decimal(8,4), @Lat2 decimal(8,4), @Long2 decimal(8,4))
returns decimal (8,4) as
begin
declare @d decimal(28,10)
-- Convert to radians
set @Lat1 = @Lat1 / 57.2958
set @Long1 = @Long1 / 57.2958
set @Lat2 = @Lat2 / 57.2958
set @Long2 = @Long2 / 57.2958
-- Calc distance
set @d = (Sin(@Lat1) * Sin(@Lat2)) + (Cos(@Lat1) * Cos(@Lat2) * Cos(@Long2 - @Long1))
-- Convert to miles
if @d <> 0
begin
set @d = 3958.75 * Atan(Sqrt(1 - power(@d, 2)) / @d);
end
return @d
end 

The below function gives distance between two geocoordinates in kilometres

CREATE FUNCTION dbo.fnCalcDistanceKM(@lat1 FLOAT, @lat2 FLOAT, @lon1 FLOAT, @lon2 FLOAT)
RETURNS FLOAT 
AS
BEGIN

    RETURN ACOS(SIN(PI()*@lat1/180.0)*SIN(PI()*@lat2/180.0)+COS(PI()*@lat1/180.0)*COS(PI()*@lat2/180.0)*COS(PI()*@lon2/180.0-PI()*@lon1/180.0))*6371
END

Usage:

select [dbo].[fnCalcDistanceKM](13.077085,80.262675,13.065701,80.258916)

The below function gives distance between two geocoordinates in kilometres using Geography data type which was introduced in sql server 2008

DECLARE @g geography;
DECLARE @h geography;
SET @g = geography::STGeomFromText('LINESTRING(-122.360 47.656, -122.343 47.656)', 4326);
SET @h = geography::STGeomFromText('POINT(-122.34900 47.65100)', 4326);
SELECT @g.STDistance(@h);

Reference: Ref1,Ref2

I hope this helps