SQL中的距离差异-为什么差异如此之大？

问题描述

如果使用两种方法计算坐标之间的距离，它们之间的差异很大（超过400 m）。你知道为什么吗？而所有计算方法中哪一种是最准确的？

第一：

DECLARE @source geography = 'POINT(53.9202690124512 14.2586479187012)'
DECLARE @target geography = 'POINT(53.8970128 14.2387088)'

SELECT @source.Stdistance(@target)

第二：

SELECT geography::Point(53.9202690124512,14.2586479187012,4326).Stdistance(geography::Point(53.8970128,14.2387088,4326))

解决方法

geography::Point希望按该顺序传递纬度和经度。 WKT的POINT希望按该顺序传递经度和纬度。查看结果：

DECLARE @wkt_source geography = 'POINT(53.9202690124512 14.2586479187012)'
DECLARE @wkt_target geography = 'POINT(53.8970128 14.2387088)'

select @wkt_source.STAsText() as wkt_source,@wkt_target.STAsText() as wkt_target

declare @point_source geography = geography::Point(53.9202690124512,14.2586479187012,4326)
declare @point_target geography = geography::Point(53.8970128,14.2387088,4326)


select @point_source.STAsText() as point_source,@point_target.STAsText() as point_target

因此，您将需要相互交换以获得一致的结果（取决于正确的经纬度）。