SDO_LRS.DEFINE_GEOM

Format

SDO_LRS.DEFINE_GEOM_SEGMENT(
     geom_segment     IN OUT SDO_GEOMETRY 
     [, start_measure IN NUMBER, 
     end_measure      IN NUMBER]);

or

SDO_LRS.DEFINE_GEOM_SEGMENT(
     geom_segment     IN OUT SDO_GEOMETRY, 
     dim_array        IN SDO_DIM_ARRAY 
     [, start_measure IN NUMBER, 
     end_measure      IN NUMBER]);

Description

Defines a geometric segment by assigning start and end measures to a geometric segment, and assigns values to any null measures.

Parameters

geom_segment: Geometric segment (LRS segment) containing measure information.
dim_array: Dimensional information array corresponding to geom_segment, usually selected from one of the xxx_SDO_GEOM_METADATA views (described in Geometry Metadata Views).
start_measure: Distance measured from the start point of a geometric segment to the start point of the linear feature. The default is the existing value (if any) in the measure dimension; otherwise, the default is 0.
end_measure: Distance measured from the end point of a geometric segment to the start point of the linear feature. The default is the existing value (if any) in the measure dimension; otherwise, the default is the cartographic length of the segment.

Usage Notes

An exception is raised if geom_segment has an invalid geometry type or dimensionality, or if start_measure or end_measure is out of range.

All unassigned measures of the geometric segment will be populated automatically.

To store the resulting geometric segment (geom_segment) in the database, you must execute an UPDATE or INSERT statement, as appropriate.

The _3D format of this procedure (SDO_LRS.DEFINE_GEOM_SEGMENT_3D) is available. For information about _3D formats of LRS functions and procedures, see 3D Formats of LRS Functions.

For more information about defining a geometric segment, see Defining a Geometric Segment .

Examples

The following example defines the geometric segment, splits it into two segments, then concatenates those segments. (This example uses the definitions from the example in Example of LRS Functions. The definitions of result_geom_1, result_geom_2, and result_geom_3 are displayed in Example 7-3.)

DECLARE
geom_segment SDO_GEOMETRY;
line_string SDO_GEOMETRY;
dim_array SDO_DIM_ARRAY;
result_geom_1 SDO_GEOMETRY;
result_geom_2 SDO_GEOMETRY;
result_geom_3 SDO_GEOMETRY;

BEGIN

SELECT a.route_geometry into geom_segment FROM lrs_routes a
  WHERE a.route_name = 'Route1';
SELECT m.diminfo into dim_array from 
  user_sdo_geom_metadata m
  WHERE m.table_name = 'LRS_ROUTES' AND m.column_name = 'ROUTE_GEOMETRY';

-- Define the LRS segment for Route1. This will populate any null measures.
SDO_LRS.DEFINE_GEOM_SEGMENT (geom_segment, 
  dim_array,
  0,    -- Zero starting measure: LRS segment starts at start of route.
  27);  -- End of LRS segment is at measure 27.

SELECT a.route_geometry INTO line_string FROM lrs_routes a 
  WHERE a.route_name = 'Route1';

-- Split Route1 into two segments.
SDO_LRS.SPLIT_GEOM_SEGMENT(line_string,dim_array,5,result_geom_1,result_geom_2);

-- Concatenate the segments that were just split.
result_geom_3 := SDO_LRS.CONCATENATE_GEOM_SEGMENTS(result_geom_1, dim_array, result_geom_2, dim_array);

-- Update and insert geometries into table, to display later.
UPDATE lrs_routes a SET a.route_geometry = geom_segment
   WHERE a.route_id = 1;

INSERT INTO lrs_routes VALUES(
  11,
  'result_geom_1',
  result_geom_1
);
INSERT INTO lrs_routes VALUES(
  12,
  'result_geom_2',
  result_geom_2
);
INSERT INTO lrs_routes VALUES(
  13,
  'result_geom_3',
  result_geom_3
);

END;
/