Format
SDO_CS.CONVERT_3D_SRID_TO_2D(
srid3d IN NUMBER) RETURN NUMBER;Description
Converts a three-dimensional SRID value into a two-dimensional SRID value.
Parameters
The SRID of a three-dimensional coordinate reference system. Must be a value in the SRID column of the SDO_COORD_REF_SYS table (described in SDO_COORD_REF_SYS Table).
Usage Notes
This function returns the SRID value of a functionally equivalent two-dimensional coordinate reference system that corresponds to the input coordinate reference system.
If a compound 3D SRID is input, there is only one corresponding two-dimensional SRID, and it is returned.
If a Geographic 3D SRID is input, there may be multiple possible corresponding two-dimensional SRIDs, and one of them is returned.
If a two-dimensional SRID is input, it is returned.
For information about three-dimensional coordinate reference system support, see Three-Dimensional Coordinate Reference System Support.
Examples
The following example returns an equivalent two-dimensional SRID for each coordinate reference system listed in the SDO_COORD_REF_SYS table (described in SDO_COORD_REF_SYS Table). For 2D SRID values in that table, the function returns the existing value.
SELECT
crs.srid "nD SRID",
crs.coord_ref_sys_kind "nD Type",
sdo_cs.convert_3d_srid_to_2d(crs.srid) "2D SRID",
(SELECT
coord_ref_sys_kind
FROM
sdo_coord_ref_sys crs2
WHERE
crs2.srid = sdo_cs.convert_3d_srid_to_2d(crs.srid)
) "2D Type"
FROM sdo_coord_ref_sys crs
ORDER BY crs.coord_ref_sys_kind,crs.srid;
nD SRID nD Type 2D SRID 2D Type
---------- ------------------------ ---------- ------------------------
4097 COMPOUND 4093 PROJECTED
4098 COMPOUND 4094 PROJECTED
4099 COMPOUND 4095 PROJECTED
… … … …
7400 COMPOUND 4807 GEOGRAPHIC2D
… … … …
5800 ENGINEERING 5800 ENGINEERING
… … … …
4000 GEOCENTRIC
… … … …
4326 GEOGRAPHIC2D 4326 GEOGRAPHIC2D
… … … …
4327 GEOGRAPHIC3D 4326 GEOGRAPHIC2D
… … … …
27700 PROJECTED 27700 PROJECTED
… … … …
3855 VERTICAL 3855 VERTICAL
… … … …