24.2 SDO_LRS.CONCATENATE_GEOM_SEGMENTS

Format

SDO_LRS.CONCATENATE_GEOM_SEGMENTS(
     geom_segment_1  IN SDO_GEOMETRY, 
     geom_segment_2  IN SDO_GEOMETRY, 
     tolerance       IN NUMBER DEFAULT 1.0e-8 
     ) RETURN SDO_GEOMETRY;

or

SDO_LRS.CONCATENATE_GEOM_SEGMENTS(
     geom_segment_1  IN SDO_GEOMETRY, 
     dim_array_1     IN SDO_DIM_ARRAY, 
     geom_segment_2  IN SDO_GEOMETRY, 
     dim_array_2     IN SDO_DIM_ARRAY 
     ) RETURN SDO_GEOMETRY;

Description

Returns the geometry object resulting from the concatenation of two geometric segments.

Parameters

geom_segment_1

First geometric segment to be concatenated.

dim_array_1

Dimensional information array corresponding to geom_segment_1, usually selected from one of the xxx_SDO_GEOM_METADATA views (described in Geometry Metadata Views).

geom_segment_2

Second geometric segment to be concatenated.

dim_array_2

Dimensional information array corresponding to geom_segment_2, usually selected from one of the xxx_SDO_GEOM_METADATA views (described in Geometry Metadata Views).

tolerance

Tolerance value (see Tolerance and Tolerance Values with LRS Functions). The default value is 0.00000001.

Usage Notes

An exception is raised if geom_segment_1 or geom_segment_2 has an invalid geometry type or dimensionality, or if geom_segment_1 and geom_segment_2 are based on different coordinate systems.

The direction of the first geometric segment is preserved, and all measures of the second segment are shifted so that its start measure is the same as the end measure of the first segment.

The geometry type of geom_segment_1 and geom_segment_2 must be line or multiline. Neither can be a polygon.

The _3D format of this function (SDO_LRS.CONCATENATE_GEOM_SEGMENTS_3D) is available. For information about _3D formats of LRS functions, see 3D Formats of LRS Functions.

For more information about concatenating geometric segments, see Concatenating Geometric Segments.

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.
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);

-- Insert geometries into table, to display later.
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;
/