sqlserver操作geography方法
参考：https://www.cnblogs.com/ytwy/p/5977848.html
http://desktop.arcgis.com/zh-cn/arcmap/latest/manage-data/using-sql-with-gdbs/a-quick-tour-of-sql-functions-used-with-st-geometry.htm
--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))
