返回一個(gè)用整數(shù)表示的輸入Geometry對(duì)象的Z/M標(biāo)志。
語(yǔ)法
smallint ST_Zmflag(geometry geomA);
參數(shù)
參數(shù)名稱 | 描述 |
---|---|
geomA | 目標(biāo)Geometry對(duì)象。 |
描述
- 數(shù)字值的含義如下:
- 0:2d
- 1:3dm
- 2:3dz
- 3:4d
- 該函數(shù)支持3D對(duì)象,并且不會(huì)刪除Z坐標(biāo)。
- 該函數(shù)支持Circular Strings和Curves類型幾何對(duì)象。
示例
不同類型的返回值:
SELECT ST_Zmflag('POINT(0 1)'::geometry) as _2D,
ST_Zmflag('POINTM(0 1 2)'::geometry) as _3DM,
ST_Zmflag('POINT(0 1 2)'::geometry) as _3DZ,
ST_Zmflag('POINT(0 1 2 3)'::geometry) as _4D;
_2d | _3dm | _3dz | _4d
-----+------+------+-----
0 | 1 | 2 | 3
(1 row)