甘肃省住房和城乡建设厅执业资格注册中心网站东莞网络推广优化排名
常用的PostGIS空间分析函数清单：
| 序号 | 函数名 | 描述 | 示例 |
|---|---|---|---|
| 1 | ST_AsText(geometry) | 将几何对象转换为文本形式的WKT字符串 | ST_AsText(ST_GeomFromText(‘POINT(1 2)’)) 返回 ‘POINT(1 2)’ |
| 2 | ST_GeometryType(geometry) | 返回几何对象的类型，如POINT、LINESTRING、POLYGON等 | ST_GeometryType(ST_GeomFromText(‘LINESTRING(1 2, 3 4)’)) 返回 ‘LINESTRING’ |
| 3 | ST_SRID(geometry) | 返回几何对象的空间参考系ID | ST_SRID(ST_GeomFromText(‘POINT(1 2)’, 4326)) 返回 4326 |
| 4 | ST_SetSRID(geometry, srid) | 设置几何对象的空间参考系ID | ST_SetSRID(ST_GeomFromText(‘POINT(1 2)’), 4326) 返回 SRID 为 4326 的 POINT(1 2) |
| 5 | ST_Dimension(geometry) | 返回几何对象的维度，如0表示点、1表示线、2表示面 | ST_Dimension(ST_GeomFromText(‘POINT(1 2)’)) 返回 0 |
| 6 | ST_Envelope(geometry) | 返回几何对象的最小外接矩形(MBR) | ST_Envelope(ST_GeomFromText(‘LINESTRING(1 2, 3 4)’)) 返回 POLYGON((1 2, 1 4, 3 4, 3 2, 1 2)) |
| 7 | ST_Length(geometry) | 计算线或多线段的长度 | ST_Length(ST_GeomFromText(‘LINESTRING(1 2, 3 4)’)) 返回 2.828427 |
| 8 | ST_Area(geometry) | 计算面或多边形的面积 | ST_Area(ST_GeomFromText(‘POLYGON((0 0, 0 1, 1 1, 1 0, 0 0))’)) 返回 1 |
| 9 | ST_Buffer(geometry, distance) | 计算几何对象的缓冲区，参数distance表示缓冲区的半径或者宽度 | ST_Buffer(ST_GeomFromText(‘POINT(1 2)’), 0.5) 返回以 POINT(1 2) 为中心，半径为0.5的圆 |
| 10 | ST_Intersection(geometry A, geometry B) | 计算两个几何对象的交集 | ST_Intersection(ST_GeomFromText(‘LINESTRING(0 0, 2 2)’), ST_GeomFromText(‘LINESTRING(1 0, 0 1)’)) 返回 POINT(0.5 0.5) |
| 11 | ST_Union(geometry A, geometry B) | 计算两个几何对象的并集 | ST_Union(ST_GeomFromText(‘LINESTRING(0 0, 1 1)’), ST_GeomFromText(‘LINESTRING(1 1, 2 2)’)) 返回 MULTILINESTRING((0 0, 1 1, 2 2)) |
| 12 | ST_Difference(geometry A, geometry B) | 计算两个几何对象的差集 | ST_Difference(ST_GeomFromText(‘LINESTRING(0 0, 2 2)’), ST_GeomFromText(‘LINESTRING(1 0, 0 1)’)) 返回 MULTILINESTRING((0 0, 1 1)) |
| 13 | ST_SymDifference(geometry A, geometry B) | 计算两个几何对象的对称差集 | ST_SymDifference(ST_GeomFromText(‘LINESTRING(0 0, 2 2)’), ST_GeomFromText(‘LINESTRING(1 0, 0 1)’)) 返回 MULTILINESTRING((0 0, 1 1), (1 1, 2 2)) |
| 14 | ST_Equals(geometry A, geometry B) | 判断两个几何对象是否相等 | ST_Equals(ST_GeomFromText(‘POINT(1 2)’), ST_GeomFromText(‘POINT(1 2)’)) 返回 true |
| 15 | ST_Disjoint(geometry A, geometry B) | 判断两个几何对象是否不相交 | ST_Disjoint(ST_GeomFromText(‘POINT(1 2)’), ST_GeomFromText(‘LINESTRING(0 0, 2 2)’)) 返回 true |
| 16 | ST_Touches(geometry A, geometry B) | 判断两个几何对象是否相接触 | ST_Touches(ST_GeomFromText(‘LINESTRING(0 0, 1 1)’), ST_GeomFromText(‘LINESTRING(1 1, 2 2)’)) 返回 true |
| 17 | ST_Crosses(geometry A, geometry B) | 判断两个几何对象是否相交但不在同一平面内 | ST_Crosses(ST_GeomFromText(‘LINESTRING(0 0, 1 1)’), ST_GeomFromText(‘LINESTRING(1 0, 0 1)’)) 返回 true |
| 18 | ST_Within(geometry A, geometry B) | 判断几何对象A是否在几何对象B内部 | ST_Within(ST_GeomFromText(‘POINT(1 2)’), ST_GeomFromText(‘POLYGON((0 0, 0 3, 3 3, 3 0, 0 0))’)) 返回 true |
| 19 | ST_Contains(geometry A, geometry B) | 判断几何对象A是否包含几何对象B | ST_Contains(ST_GeomFromText(‘POLYGON((0 0, 0 3, 3 3, 3 0, 0 0))’), ST_GeomFromText(‘POINT(1 2)’)) 返回 true |
| 20 | ST_Intersects(geometry A, geometry B) | 判断两个几何对象是否相交 | ST_Intersects(ST_GeomFromText(‘POINT(1 2)’), ST_GeomFromText(‘LINESTRING(0 0, 2 2)’)) 返回 true |
| 21 | ST_Centroid(geometry) | 计算几何对象的中心点 | ST_Centroid(ST_GeomFromText(‘POLYGON((0 0, 0 3, 3 3, 3 0, 0 0))’)) 返回 POINT(1.5 1.5) |
| 22 | ST_PointOnSurface(geometry) | 计算几 何对象的表面上的点 | ST_PointOnSurface(ST_GeomFromText(‘POLYGON((0 0, 0 3, 3 3, 3 0, 0 0))’)) 返回 POINT(1.5 1.5) |
| 23 | ST_Transform(geometry, srid) | 将几何对象从一个空间参考系转换为另一个空间参考系 | ST_Transform(ST_GeomFromText(‘POINT(1 2)’, 4326), 3857) 返回在Web墨卡托投影下的 POINT(111319.49079327357 222684.20875941086) |
| 24 | ST_Distance(geometry A, geometry B) | 计算两个几何对象之间的距离 | ST_Distance(ST_GeomFromText(‘POINT(1 2)’), ST_GeomFromText(‘POINT(3 4)’)) 返回 2.828427 |
| 25 | ST_Distance_Sphere(geometry A, geometry B) | 计算两个几何对象之间的球面距离，单位为米 | ST_Distance_Sphere(ST_GeomFromText(‘POINT(1 2)’, 4326), ST_GeomFromText(‘POINT(3 4)’, 4326)) 返回 314274.3882001206 |
| 26 | ST_Azimuth(geometry A, geometry B) | 计算从几何对象A到几何对象B的方位角，单位为弧度 | ST_Azimuth(ST_GeomFromText(‘POINT(1 2)’, 4326), ST_GeomFromText(‘POINT(3 4)’, 4326)) 返回 0.785398 |
| 27 | ST_MakePoint(x, y) | 创建一个二维点 | ST_MakePoint(1, 2) 返回 POINT(1 2) |
| 28 | ST_MakeLine(geometry A, geometry B, …) | 创建一个线段 | ST_MakeLine(ST_MakePoint(1, 2), ST_MakePoint(3, 4)) 返回 LINESTRING(1 2, 3 4) |
| 29 | ST_MakePolygon(geometry A, geometry B, …) | 创建一个多边形 | ST_MakePolygon(ST_MakeLine(ST_MakePoint(1, 2), ST_MakePoint(3, 4), ST_MakePoint(5, 6), ST_MakePoint(1, 2))) 返回 POLYGON((1 2, 3 4, 5 6, 1 2)) |
| 30 | ST_GeomFromText(text) | 从WKT字符串创建几何对象 | ST_GeomFromText(‘POINT(1 2)’) 返回 POINT(1 2) |