描述

返回多面体曲面上的面数。对于非多面体几何图形，将返回NULL。这是ST_NumGeometries的别名，用于支持MM命名。如果您不关心MM约定，则使用ST_NumGeometries的速度更快。

可用性：2.0.0

This function supports 3d and will not drop the z-index.

This method implements the OGC Simple Features Implementation Specification for SQL 1.1.

This method implements the SQL/MM specification. SQL-MM 3：？

This function supports Polyhedral surfaces.

示例

SELECT ST_NumPatches(ST_GeomFromEWKT('POLYHEDRALSURFACE( ((0 0 0, 0 0 1, 0 1 1, 0 1 0, 0 0 0)),
                ((0 0 0, 0 1 0, 1 1 0, 1 0 0, 0 0 0)), ((0 0 0, 1 0 0, 1 0 1, 0 0 1, 0 0 0)),
                ((1 1 0, 1 1 1, 1 0 1, 1 0 0, 1 1 0)),
                ((0 1 0, 0 1 1, 1 1 1, 1 1 0, 0 1 0)), ((0 0 1, 1 0 1, 1 1 1, 0 1 1, 0 0 1)) )'));
                --result
                6
                

另请参阅

ST_GeomFromEWKT, ST_NumGeometries