SqlServer中Geography的使用

地理空间数据类型 geography 是作为 SQL Server 中的 .NET 公共语言运行时 (CLR) 数据类型实现的。 此类型表示圆形地球坐标系中的数据。 geography 数据类型存储椭球体（圆形地球）数据，如 GPS 纬度和经度坐标SQL Server 。 SQL Server 支持 geography 空间数据类型的一组方法。 这些方法包括开放地理空间信息联盟 (OGC) 标准和对该标准的一组 Microsoft 扩展所定义的 geography 方法。 SQL Server 2008 在几何图形实例上支持开放地理空间联盟 (OGC) 方法。

地理空间数据类型 geography 是作为 SQL Server 中的 .NET 公共语言运行时 (CLR) 数据类型实现的。 此类型表示圆形地球坐标系中的数据。 geography 数据类型存储椭球体（圆形地球）数据，如 GPS 纬度和经度坐标SQL Server 。 SQL Server 支持 geography 空间数据类型的一组方法。 这些方法包括开放地理空间信息联盟 (OGC) 标准和对该标准的一组 Microsoft 扩展所定义的 geography 方法。

--总表面积
SELECT geography::STGeomFromText('POLYGON((-122.358 47.653, -122.348 47.649, -122.348 47.658, -122.358 47.658, -122.358 47.653))', 4326).STArea()--二进制（WKB）表示形式
SELECT geography::STGeomFromText('LINESTRING( -122.360 47.656, -122.343 47.656)', 4326).STAsBinary()--WKT表示形式
SELECT geography::STGeomFromText('LINESTRING(-122.360 47.656, -122.343 47.656)', 4326).STAsText()--缓冲区
SELECT geography::STGeomFromText('LINESTRING(-122.360 47.656, -122.343 47.656)', 4326).STBuffer(1)--返回指定的曲线
SELECT geography::STGeomFromText('COMPOUNDCURVE (CIRCULARSTRING (-122.358 47.653, -122.348 47.649, -122.348 47.658), CIRCULARSTRING(-122.348 47.658, -122.358 47.658, -122.358 47.653))',4326).STCurveN(2)--圆弧线段的多边形近似值
SELECT geography::STGeomFromText('CIRCULARSTRING(-122.358 47.653, -122.348 47.649, -122.348 47.658, -122.358 47.658, -122.358 47.653)',4326).STCurveToLine()--差集
SELECT geography::STGeomFromText('POLYGON((-122.358 47.653, -122.348 47.649, -122.348 47.658, -122.358 47.658, -122.358 47.653))', 4326).STDifference(geography::STGeomFromText('LINESTRING(-122.360 47.656, -122.343 47.656)', 4326))--最大维度
SELECT geography::STGeomFromText('POLYGON((-122.358 47.653, -122.348 47.649, -122.348 47.658, -122.358 47.658, -122.358 47.653))', 4326).STDimension()--是否不相联
SELECT geography::STGeomFromText('LINESTRING(-122.360 47.656, -122.343 47.656)', 4326).STDisjoint(geography::STGeomFromText('POINT( -122.343 47.656)', 4326))--距离
SELECT geography::STGeomFromText('LINESTRING(-122.360 47.656, -122.343 47.656)', 4326).STDistance(geography::STGeomFromText('POINT(-122.34900 47.65100)', 4326))--终点
SELECT geography::STGeomFromText('LINESTRING(-122.360 47.656, -122.343 47.656)', 4326).STEndPoint()--判断是否相等
SELECT geography::STGeomFromText('GEOMETRYCOLLECTION(POLYGON((-122.368 47.658, -122.338 47.649, -122.338 47.658, -122.368 47.658, -122.368 47.658)), LINESTRING(-122.360 47.656, -122.343 47.656), POINT (-122.35 47.656))', 4326).STEquals(geography::STGeomFromText('POLYGON((-122.368 47.658, -122.338 47.649, -122.338 47.658, -122.368 47.658, -122.368 47.658))', 4326))--查找GeometryCollection中第n个实例
SELECT geography::STGeomFromText('MULTIPOINT(-122.360 47.656, -122.343 47.656)', 4326).STGeometryN(2)--类型
SELECT geometry::STGeomFromText('POLYGON((-122.358 47.653, -122.348 47.649, -122.348 47.658, -122.358 47.658, -122.358 47.653))', 4326).STGeometryType()--交集
SELECT geography::STGeomFromText('POLYGON((-122.358 47.653, -122.348 47.649, -122.348 47.658, -122.358 47.658, -122.358 47.653))', 4326).STIntersection(geography::STGeomFromText('LINESTRING(-122.360 47.656, -122.343 47.656)', 4326))--判断是否相交
SELECT geography::STGeomFromText('POLYGON((-122.358 47.653, -122.348 47.649, -122.348 47.658, -122.358 47.658, -122.358 47.653))', 4326).STIntersects(geography::STGeomFromText('LINESTRING(-122.360 47.656, -122.343 47.656)', 4326))--判断是否闭合
SELECT geography::STGeomFromText('POLYGON((-122.358 47.653, -122.348 47.649, -122.348 47.658, -122.358 47.658, -122.358 47.653))', 4326).STIsClosed()--判断是否为空
SELECT geography::STGeomFromText('POLYGON EMPTY', 4326).STIsEmpty()--判断是否为有效geography格式
SELECT geography::STGeomFromText('LINESTRING(0 0, 2 2, 1 0)', 4326).STIsValid()--边长总长度
SELECT geography::STGeomFromText('POLYGON((-122.358 47.653, -122.348 47.649, -122.348 47.658, -122.358 47.658, -122.358 47.653))', 4326).STLength()--一维geography曲线数
SELECT geography::STGeomFromText('COMPOUNDCURVE(CIRCULARSTRING(-122.358 47.653, -122.348 47.649, -122.348 47.658, -122.358 47.658, -122.358 47.653))',4326).STNumCurves()--geometry数量
SELECT geography::STGeomFromText('MULTIPOINT((-122.360 47.656), (-122.343 47.656))', 4326).STNumGeometries()--点数量
SELECT geography::STGeomFromText('GEOMETRYCOLLECTION(CIRCULARSTRING(-122.358 47.653, -122.348 47.649, -122.348 47.658, -122.358 47.658, -122.358 47.653) ,CURVEPOLYGON(CIRCULARSTRING(-122.358 47.653, -122.348 47.649, -122.348 47.658, -122.358 47.658, -122.358 47.653)))', 4326).STNumPoints()--指定点
SELECT geography::STGeomFromText('LINESTRING(-122.360 47.656, -122.343 47.656)', 4326).STPointN(2)--空间参考
SELECT geography::STGeomFromText('LINESTRING(-122.360 47.656, -122.343 47.656)', 4326).STSrid--起点
SELECT geography::STGeomFromText('LINESTRING(-122.360 47.656, -122.343 47.656)', 4326).STStartPoint()--余集
SELECT geography::STGeomFromText('POLYGON((-122.358 47.653, -122.348 47.649, -122.348 47.658, -122.358 47.658, -122.358 47.653))', 4326).STSymDifference(geography::STGeomFromText('POLYGON((-122.351 47.656, -122.341 47.656, -122.341 47.661, -122.351 47.661, -122.351 47.656))', 4326))--并集
SELECT geography::STGeomFromText('POLYGON((-122.358 47.653, -122.348 47.649, -122.348 47.658, -122.358 47.658, -122.358 47.653))', 4326).STUnion(geography::STGeomFromText('POLYGON((-122.351 47.656, -122.341 47.656, -122.341 47.661, -122.351 47.661, -122.351 47.656))', 4326))

官方资料：

https://docs.microsoft.com/zh-cn/previous-versions/sql/sql-server-2008/bb933960(v=sql.100)

https://docs.microsoft.com/zh-cn/sql/t-sql/spatial-geography/spatial-types-geography?view=sql-server-ver15

https://desktop.arcgis.com/zh-cn/arcmap/latest/manage-data/using-sql-with-gdbs/a-quick-tour-of-sql-functions-used-with-st-geometry.htm