6.7 SDO_NET.COMPUTE_PATH_GEOMETRY

Format

SDO_NET.COMPUTE_PATH_GEOMETRY(
     network   IN VARCHAR2,
     path_id   IN NUMBER,
     tolerance IN NUMBER
) RETURN SDO_GEOMETRY;

Description

Returns the spatial geometry for a path.

Parameters

network

Network name.

path_id

Path ID number.

tolerance

Tolerance value associated with geometries in the network. (Tolerance is explained in Chapter 1 of Oracle Spatial Developer's Guide.) This value should be consistent with the tolerance values of the geometries in the link table and node table for the network.

Usage Notes

This function computes and returns the SDO_GEOMETRY object for the specified path.

This function and the SDO_NET_MEM.PATH.COMPUTE_GEOMETRY procedure (documented in SDO_NET Package Subprograms) both compute a path geometry, but they have the following differences:

  • The SDO_NET.COMPUTE_PATH_GEOMETRY function computes the path from the links in the database, and does not use a network memory object. It returns the path geometry.

  • The SDO_NET_MEM.PATH.COMPUTE_GEOMETRY procedure computes the path using a network memory object that has been loaded. It does not return the path geometry; you must use the SDO_NET_MEM.PATH.GET_GEOMETRY function to get the geometry.

Examples

The following example computes and returns the spatial geometry of the path with path ID 1 in the network named SDO_NET1, using a tolerance value of 0.005. The returned path geometry is a straight line from (1,1) to (15,1) because this path consists of a single link.

SELECT SDO_NET.COMPUTE_PATH_GEOMETRY('SDO_NET1', 1, 0.005) FROM DUAL;
 
SDO_NET.COMPUTE_PATH_GEOMETRY('SDO_NET1',1,0.005)(SDO_GTYPE, SDO_SRID, SDO_POINT
--------------------------------------------------------------------------------
SDO_GEOMETRY(2002, NULL, NULL, SDO_ELEM_INFO_ARRAY(1, 2, 1), SDO_ORDINATE_ARRAY(
1, 1, 15, 1))