问题
Recently, I was studying spatialite.I can write 2D data(like this:POINT(1 1)) into the spatial data table,but I can't write 3D data(like this:POINT(1 1 1) ) into the spatial data table. Who can tell me spatialite whether support 3D? If support ,how can I write a 3D data?
回答1:
Yes, Spatialite supports 3D geometries (actually 2.5D geometries).
On why it does not work for you, probably your geometry column is not defined as XYZ
. You can check geometry metadata with the query:
SELECT * FROM geometry_columns;
回答2:
To add points with three 3 dimensions you have to use the correct WKT expression: POINTZ(x,y,z)
.
(see also: https://www.gaia-gis.it/gaia-sins/spatialite-cookbook/html/wkt-wkb.html)
You also have to make sure, that you geometry column is correctly defined as XYZ column. (see functions: Dimension
CoordDimension
Is3D
). GeometryType
should therefore return POINTZ
(see also: http://www.gaia-gis.it/gaia-sins/spatialite-sql-4.2.0.html)
来源:https://stackoverflow.com/questions/45992529/does-spatialite-mysql-support-3d-point