1. RDF Semantic Graph Developer's Guide
  2. SEM_MATCH Support for Spatial Queries

B SEM_MATCH Support for Spatial Queries

This appendix provides reference information for SPARQL extension functions for performing spatial queries in SEM_MATCH.

To use these functions, you must understand the concepts explained in Spatial Support.

Note:

Throughout this appendix geomLiteral is used as a placeholder for orageo:WKTLiteral, ogc:wktLiteral, and ogc:gmlLiteral, which can be used interchangeably, in format representations and parameter descriptions. (However, orageo:WKTLiteral or ogc:wktLiteral is used in actual examples.)

This appendix includes the following GeoSPARQL and Oracle-specific functions:

GeoSPARQL functions:

Oracle-specific functions:

B.1 ogcf:boundary

Format

ogcf:boundary(geom : geomLiteral) : ogc:wktLiteral

Description

Returns a geometry object that is the closure of the boundary of geom.

Parameters

geom

Geometry object. Specified as a query variable or a constant geomLiteral value.

Usage Notes

See Spatial Support for information about representing , indexing, and querying spatial data in RDF.

See also the OGC GeoSPARQL specification.

Example

The following example finds the boundaries of U.S. Congressional district polygons.

SELECT cb
FROM table(sem_match(
'SELECT (ogcf:boundary(?cgeom) AS ?cb)
 WHERE
 { ?person usgovt:name ?name .
   ?person pol:hasRole ?role .
   ?role pol:forOffice ?office .
   ?office pol:represents ?cdist .
   ?cdist orageo:hasExactGeometry ?cgeom }'
,sem_models('gov_all_vm'), null, 
,sem_aliases(
   sem_alias('usgovt','http://www.rdfabout.com/rdf/schema/usgovt/'),
   sem_alias('pol','http://www.rdfabout.com/rdf/schema/politico/')
   )
,null, null, null, ' ALLOW_DUP=T '));

Parent topic: SEM_MATCH Support for Spatial Queries

B.2 ogcf:buffer

Format

ogcf:buffer(geom : geomLiteral, radius : xsd:decimal, units : xsd:anyURI) : ogc:wktLiteral

Description

Returns a buffer polygon the specified radius (measured in units) around a geometry.

Parameters

geom

Geometry object. Specified as a query variable or a constant geomLiteral value.

radius

Radius value used to define the buffer.

units

Unit of measurement: a URI of the form <http://xmlns.oracle.com/rdf/geo/uom/{SDO_UNIT}> (for example, <http://xmlns.oracle.com/rdf/geo/uom/KM>). Any SDO_UNIT value from the MDSYS.SDO_DIST_UNITS table will be recognized. See the section about unit of measurement support in Oracle Spatial and Graph Developer's Guide for more information about unit of measurement specification.

Usage Notes

See Spatial Support for information about representing , indexing, and querying spatial data in RDF.

See also the OGC GeoSPARQL specification.

Example

The following example finds the U.S. Congressional district polygons that are within a 100 kilometer buffer around a specified point.

SELECT name, cdist
FROM table(sem_match(
'{ # HINT0={LEADING(?cgeom)}
   ?person usgovt:name ?name .
   ?person pol:hasRole ?role .
   ?role pol:forOffice ?office .
   ?office pol:represents ?cdist .
   ?cdist orageo:hasExactGeometry ?cgeom 
   FILTER (
     ogcf:sfWithin(?cgeom, 
       ogcf:buffer("POINT(-71.46444 42.7575)"^^ogc:wktLiteral,
                     100, 
                     <http://xmlns.oracle.com/rdf/geo/uom/KM>)) }'
,sem_models('gov_all_vm'), null, 
,sem_aliases(
   sem_alias('usgovt','http://www.rdfabout.com/rdf/schema/usgovt/'),
   sem_alias('pol','http://www.rdfabout.com/rdf/schema/politico/')
   )
,null, null, null, ' ALLOW_DUP=T '));

Parent topic: SEM_MATCH Support for Spatial Queries

B.3 ogcf:convexHull

Format

ogcf:convexHull(geom : geomLiteral) : ogc:wktLiteral

Description

Returns a polygon geometry that represents the convex hull of geom. (The convex hull is a simple convex polygon that completely encloses the geometry object, using as few straight-line sides as possible to create the smallest polygon that completely encloses the geometry object.)

Parameters

geom

Geometry object. Specified as a query variable or a constant geomLiteral value.

Usage Notes

See Spatial Support for information about representing , indexing, and querying spatial data in RDF.

See also the OGC GeoSPARQL specification.

Example

The following example finds the U.S. Congressional district polygons whose convex hull contains a specified point.

SELECT name, cdist
FROM table(sem_match(
'{ ?person usgovt:name ?name .
   ?person pol:hasRole ?role .
   ?role pol:forOffice ?office .
   ?office pol:represents ?cdist .
   ?cdist orageo:hasExactGeometry ?cgeom 
   FILTER (ogcf:sfContains(ogcf:convexHull(?cgeom), 
      "POINT(-71.46444 42.7575)"^^ogc:wktLiteral)) } '
,sem_models('gov_all_vm'), null, 
,sem_aliases(
   sem_alias('usgovt','http://www.rdfabout.com/rdf/schema/usgovt/'),
   sem_alias('pol','http://www.rdfabout.com/rdf/schema/politico/')
   )
,null, null, null, ' ALLOW_DUP=T '));

Parent topic: SEM_MATCH Support for Spatial Queries

B.4 ogcf:difference

Format

ogcf:difference(geom1 : geomLiteral, geom2 : geomLiteral) : ogc:wktLiteral

Description

Returns a geometry object that is the topological difference (MINUS operation) of geom1 and geom2.

Parameters

geom1

Geometry object. Specified as a query variable or a constant geomLiteral value.

geom2

Geometry object. Specified as a query variable or a constant geomLiteral value.

Usage Notes

See Spatial Support for information about representing , indexing, and querying spatial data in RDF.

See also the OGC GeoSPARQL specification.

Example

The following example finds the U.S. Congressional district polygons whose centroid is within the difference of two specified polygons.

SELECT name, cdist
FROM table(sem_match(
'{ ?person usgovt:name ?name .
   ?person pol:hasRole ?role .
   ?role pol:forOffice ?office .
   ?office pol:represents ?cdist .
   ?cdist orageo:hasExactGeometry ?cgeom 
   FILTER (ogcf:sfWithin(orageo:centroid(?cgeom), 
        ogcf:difference("Polygon((-83.6 34.1, -83.2 34.1, -83.2 34.5, 
                         -83.6 34.5, -83.6 34.1))"^^ogc:wktLiteral,
                        "Polygon((-83.2 34.3, -83.0 34.3, -83.0 34.5, 
                         -83.2 34.5, -83.2 34.3))"^^ogc:wktLiteral))) } '
,sem_models('gov_all_vm'), null, 
,sem_aliases(
   sem_alias('usgovt','http://www.rdfabout.com/rdf/schema/usgovt/'),
   sem_alias('pol','http://www.rdfabout.com/rdf/schema/politico/')
   )
,null, null, null, ' ALLOW_DUP=T '));

Parent topic: SEM_MATCH Support for Spatial Queries

B.5 ogcf:distance

Format

ogcf:distance(geom1 : geomLiteral, geom2 : geomLiteral, units : xsd:anyURI) : xsd:decimal

Description

Returns the distance in units between the two closest points of geom1 and geom2.

Parameters

geom1

Geometry object. Specified as a query variable or a constant geomLiteral value.

geom2

Geometry object. Specified as a query variable or a constant geomLiteral value.

units

Unit of measurement: a URI of the form <http://xmlns.oracle.com/rdf/geo/uom/{SDO_UNIT}> (for example, <http://xmlns.oracle.com/rdf/geo/uom/KM>). Any SDO_UNIT value from the MDSYS.SDO_DIST_UNITS table will be recognized. See the section about unit of measurement support in Oracle Spatial and Graph Developer's Guide for more information about unit of measurement specification.

Usage Notes

See Spatial Support for information about representing , indexing, and querying spatial data in RDF.

See also the OGC GeoSPARQL specification.

Example

The following example orders U.S. Congressional districts based on distance from a specified point.

SELECT name, cdist
FROM table(sem_match(
'SELECT ?name ?cdist
 WHERE
 { # HINT0={LEADING(?cgeom)}
   ?person usgovt:name ?name .
   ?person pol:hasRole ?role .
   ?role pol:forOffice ?office .
   ?office pol:represents ?cdist .
   ?cdist orageo:hasExactGeometry ?cgeom 
 }
 ORDER BY ASC(ogcf:distance(?cgeom,
                "POINT(-71.46444 42.7575)"^^ogc:wktLiteral,
                <http://xmlns.oracle.com/rdf/geo/uom/KM>))'
,sem_models('gov_all_vm'), null, 
,sem_aliases(
   sem_alias('usgovt','http://www.rdfabout.com/rdf/schema/usgovt/'),
   sem_alias('pol','http://www.rdfabout.com/rdf/schema/politico/')
   )
,null, null, null, ' ALLOW_DUP=T '))
ORDER BY sem$rownum;

Parent topic: SEM_MATCH Support for Spatial Queries

B.6 ogcf:envelope

Format

ogcf:envelope(geom : geomLiteral) : ogc:wktLiteral

Description

Returns the minimum bounding rectangle (MBR) of geom, that is, the single rectangle that minimally encloses geom.

Parameters

geom

Geometry object. Specified as a query variable or a constant geomLiteral value.

Usage Notes

See Spatial Support for information about representing , indexing, and querying spatial data in RDF.

See also the OGC GeoSPARQL specification.

Example

The following example finds the U.S. Congressional district polygons whose minimum bounding rectangle contains a specified point.

SELECT name, cdist
FROM table(sem_match(
'{ ?person usgovt:name ?name .
   ?person pol:hasRole ?role .
   ?role pol:forOffice ?office .
   ?office pol:represents ?cdist .
   ?cdist orageo:hasExactGeometry ?cgeom 
   FILTER (ogcf:sfContains(ogcf:envelope(?cgeom), 
      "POINT(-71.46444 42.7575)"^^ogc:wktLiteral)) } '
,sem_models('gov_all_vm'), null, 
,sem_aliases(
   sem_alias('usgovt','http://www.rdfabout.com/rdf/schema/usgovt/'),
   sem_alias('pol','http://www.rdfabout.com/rdf/schema/politico/')
   )
,null, null, null, ' ALLOW_DUP=T '));

Parent topic: SEM_MATCH Support for Spatial Queries

B.7 ogcf:getSRID

Format

ogcf:getSRID(geom : geomLiteral) : xsd:anyURI

Description

Returns the spatial reference system URI for geom.

Parameters

geom

Geometry object. Specified as a query variable or a constant geomLiteral value.

Usage Notes

See Spatial Support for information about representing , indexing, and querying spatial data in RDF.

See also the OGC GeoSPARQL specification.

Example

The following example finds spatial reference system URIs for U.S. Congressional district polygons.

SELECT csrid
FROM table(sem_match(
'SELECT (ogcf:getSRID(?cgeom) AS ?csrid)
 WHERE
 { ?person usgovt:name ?name .
   ?person pol:hasRole ?role .
   ?role pol:forOffice ?office .
   ?office pol:represents ?cdist .
   ?cdist orageo:hasExactGeometry ?cgeom }'
,sem_models('gov_all_vm'), null, 
,sem_aliases(
   sem_alias('usgovt','http://www.rdfabout.com/rdf/schema/usgovt/'),
   sem_alias('pol','http://www.rdfabout.com/rdf/schema/politico/')
   )
,null, null, null, ' ALLOW_DUP=T '));

Parent topic: SEM_MATCH Support for Spatial Queries

B.8 ogcf:intersection

Format

ogcf:intersection (geom1 : geomLiteral, geom2 : geomLiteral) : ogc:wktLiteral

Description

Returns a geometry object that is the topological intersection (AND operation) of geom1 and geom2.

Parameters

geom1

Geometry object. Specified as a query variable or a constant geomLiteral value.

geom2

Geometry object. Specified as a query variable or a constant geomLiteral value.

Usage Notes

See Spatial Support for information about representing , indexing, and querying spatial data in RDF.

See also the OGC GeoSPARQL specification.

Example

The following example finds the U.S. Congressional district polygons whose centroid is within the intersection of two specified polygons.

SELECT name, cdist
FROM table(sem_match(
'{ ?person usgovt:name ?name .
   ?person pol:hasRole ?role .
   ?role pol:forOffice ?office .
   ?office pol:represents ?cdist .
   ?cdist orageo:hasExactGeometry ?cgeom 
   FILTER (ogcf:sfWithin(orageo:centroid(?cgeom), 
        ogcf:intersection("Polygon((-83.6 34.1, -83.2 34.1, -83.2 34.5, 
                           -83.6 34.5, -83.6 34.1))"^^ogc:wktLiteral,
                          "Polygon((-83.2 34.3, -83.0 34.3, -83.0 34.5, 
                           -83.2 34.5, -83.2 34.3))"^^ogc:wktLiteral))) } '
,sem_models('gov_all_vm'), null, 
,sem_aliases(
   sem_alias('usgovt','http://www.rdfabout.com/rdf/schema/usgovt/'),
   sem_alias('pol','http://www.rdfabout.com/rdf/schema/politico/')
   )
,null, null, null, ' ALLOW_DUP=T '));

Parent topic: SEM_MATCH Support for Spatial Queries

B.9 ogcf:relate

Format

ogcf:relate(geom1 : geomLiteral, geom2 : geomLiteral, pattern-matrix : xsd:string) : xsd:boolean

Description

Returns true if the topological relationship between geom1 and geom2 satisfies the specified DE-9IM pattern-matrix. Returns false otherwise.

Parameters

geom1

Geometry object. Specified as a query variable or a constant geomLiteral value.

geom2

Geometry object. Specified as a query variable or a constant geomLiteral value.

pattern-matrix

A dimensionally extended 9-intersection model (DE-9IM) intersection pattern string consisting of T (true) and F (false) values. A DE-9IM pattern string describes the intersections between the interiors, boundaries, and exteriors of two geometries.

Usage Notes

When invoking ogcf:relate with a query variable and a constant geometry, always use the query variable as the first parameter and the constant geometry as the second parameter.

For best performance, geom1 should be a local variable (that is, a variable that appears in the basic graph pattern that contains the ogcf:relate spatial filter).

It is recommended to use a LEADING(?var) HINT0 hint when the query involves a restrictive ogcf:relate spatial filter on ?var.

See Spatial Support for information about representing , indexing, and querying spatial data in RDF.

See the OGC Simple Features Specification (OGC 06-103r3) for a detailed description of DE-9IM intersection patterns. See also the OGC GeoSPARQL specification.

Example

The following example finds the U.S. Congressional district that contains a specified point.

SELECT name, cdist
FROM table(sem_match(
'{ # HINT0={LEADING(?cgeom)}
   ?person usgovt:name ?name .
   ?person pol:hasRole ?role .
   ?role pol:forOffice ?office .
   ?office pol:represents ?cdist .
   ?cdist orageo:hasExactGeometry ?cgeom 
   FILTER (ogcf:relate(?cgeom, 
      "POINT(-71.46444 42.7575)"^^ogc:wktLiteral,
      "TTTFFTFFT")) } '
,sem_models('gov_all_vm'), null, 
,sem_aliases(
   sem_alias('usgovt','http://www.rdfabout.com/rdf/schema/usgovt/'),
   sem_alias('pol','http://www.rdfabout.com/rdf/schema/politico/')
   )
,null, null, null, ' ALLOW_DUP=T '
));

Parent topic: SEM_MATCH Support for Spatial Queries

B.10 ogcf:sfContains

Format

ogcf:sfContains(geom1 : geomLiteral, geom2 : geomLiteral) : xsd:boolean

Description

Returns true if geom1 spatially contains geom2 as defined by the OGC Simple Features specification (OGC 06-103r3). Returns false otherwise.

Parameters

geom1

Geometry object. Specified as a query variable or a constant geomLiteral value.

geom2

Geometry object. Specified as a query variable or a constant geomLiteral value.

Usage Notes

When invoking this function with a query variable and a constant geometry, always use the query variable as the first parameter and the constant geometry as the second parameter.

For best performance, geom1 should be a local variable (that is, a variable that appears in the basic graph pattern that contains the ogcf:sfContains spatial filter).

It is recommended to use a LEADING(?var) HINT0 hint when the query involves a restrictive ogcf:sfContains spatial filter on ?var.

See Spatial Support for information about representing , indexing, and querying spatial data in RDF.

See also the OGC GeoSPARQL specification.

Example

The following example finds U.S. Congressional district polygons that spatially contain a constant polygon.

SELECT name, cdist
FROM table(sem_match(
'{ # HINT0={LEADING(?cgeom)}
   ?person usgovt:name ?name .
   ?person pol:hasRole ?role .
   ?role pol:forOffice ?office .
   ?office pol:represents ?cdist .
   ?cdist orageo:hasExactGeometry ?cgeom 
   FILTER (ogcf:sfContains(?cgeom, 
             "Polygon((-83.6 34.1, -83.2 34.1, -83.2 34.5, 
                       -83.6 34.5, -83.6 34.1))"^^ogc:wktLiteral)) } '
,sem_models('gov_all_vm'), null, 
,sem_aliases(
   sem_alias('usgovt','http://www.rdfabout.com/rdf/schema/usgovt/'),
   sem_alias('pol','http://www.rdfabout.com/rdf/schema/politico/')
   )
,null, null, null, ' ALLOW_DUP=T '));

Parent topic: SEM_MATCH Support for Spatial Queries

B.11 ogcf:sfCrosses

Format

ogcf:sfCrosses(geom1 : geomLiteral, geom2 : geomLiteral) : xsd:boolean

Description

Returns true if geom1 spatially crosses geom2 as defined by the OGC Simple Features specification (OGC 06-103r3). Returns false otherwise.

Parameters

geom1

Geometry object. Specified as a query variable or a constant geomLiteral value.

geom2

Geometry object. Specified as a query variable or a constant geomLiteral value.

Usage Notes

When invoking this function with a query variable and a constant geometry, always use the query variable as the first parameter and the constant geometry as the second parameter.

For best performance, geom1 should be a local variable (that is, a variable that appears in the basic graph pattern that contains the ogcf:sfCrosses spatial filter).

It is recommended to use a LEADING(?var) HINT0 hint when the query involves a restrictive ogcf:sfCrosses spatial filter on ?var.

See Spatial Support for information about representing , indexing, and querying spatial data in RDF.

See also the OGC GeoSPARQL specification.

Example

The following example finds U.S. Congressional district polygons that spatially cross a constant polygon.

SELECT name, cdist
FROM table(sem_match(
'{ # HINT0={LEADING(?cgeom)}
   ?person usgovt:name ?name .
   ?person pol:hasRole ?role .
   ?role pol:forOffice ?office .
   ?office pol:represents ?cdist .
   ?cdist orageo:hasExactGeometry ?cgeom 
   FILTER (ogcf:sfCrosses(?cgeom, 
             "Polygon((-83.6 34.1, -83.2 34.1, -83.2 34.5, 
                       -83.6 34.5, -83.6 34.1))"^^ogc:wktLiteral)) } '
,sem_models('gov_all_vm'), null, 
,sem_aliases(
   sem_alias('usgovt','http://www.rdfabout.com/rdf/schema/usgovt/'),
   sem_alias('pol','http://www.rdfabout.com/rdf/schema/politico/')
   )
,null, null, null, ' ALLOW_DUP=T '));

Parent topic: SEM_MATCH Support for Spatial Queries

B.12 ogcf:sfDisjoint

Format

ogcf:fDisjoint(geom1 : geomLiteral, geom2 : geomLiteral) : xsd:boolean

Description

Returns true if the two geometries are spatially disjoint as defined by the OGC Simple Features specification (OGC 06-103r3). Returns false otherwise.

Parameters

geom1

Geometry object. Specified as a query variable or a constant geomLiteral value.

geom2

Geometry object. Specified as a query variable or a constant geomLiteral value.

Usage Notes

The ogcf:sfDisjoint filter cannot use a spatial index for evaluation, so performance will probably be much worse than with other simple features spatial functions.

See also the OGC GeoSPARQL specification.

Example

The following example finds U.S. Congressional district polygons that are spatially disjoint from a constant polygon.

SELECT name, cdist
FROM table(sem_match(
'{ ?person usgovt:name ?name .
   ?person pol:hasRole ?role .
   ?role pol:forOffice ?office .
   ?office pol:represents ?cdist .
   ?cdist orageo:hasExactGeometry ?cgeom 
   FILTER (ogcf:sfDisjoint(?cgeom, 
             "Polygon((-83.6 34.1, -83.2 34.1, -83.2 34.5, 
                       -83.6 34.5, -83.6 34.1))"^^ogc:wktLiteral)) } '
,sem_models('gov_all_vm'), null, 
,sem_aliases(
   sem_alias('usgovt','http://www.rdfabout.com/rdf/schema/usgovt/'),
   sem_alias('pol','http://www.rdfabout.com/rdf/schema/politico/')
   )
,null, null, null, ' ALLOW_DUP=T '));

Parent topic: SEM_MATCH Support for Spatial Queries

B.13 ogcf:sfEquals

Format

ogcf:sfEquals(geom1 : geomLiteral, geom2 : geomLiteral) : xsd:boolean

Description

Returns true if the two geometries are spatially equal as defined by the OGC Simple Features specification (OGC 06-103r3). Returns false otherwise.

Parameters

geom1

Geometry object. Specified as a query variable or a constant geomLiteral value.

geom2

Geometry object. Specified as a query variable or a constant geomLiteral value.

Usage Notes

When invoking this function with a query variable and a constant geometry, always use the query variable as the first parameter and the constant geometry as the second parameter.

For best performance, geom1 should be a local variable (that is, a variable that appears in the basic graph pattern that contains the ogcf:sfEquals spatial filter).

It is recommended to use a LEADING(?var) HINT0 hint when the query involves a restrictive ogcf:sfEquals spatial filter on ?var.

See Spatial Support for information about representing , indexing, and querying spatial data in RDF.

See also the OGC GeoSPARQL specification.

Example

The following example finds U.S. Congressional district polygons that are spatially equal to a constant polygon.

SELECT name, cdist
FROM table(sem_match(
'{ # HINT0={LEADING(?cgeom)}
   ?person usgovt:name ?name .
   ?person pol:hasRole ?role .
   ?role pol:forOffice ?office .
   ?office pol:represents ?cdist .
   ?cdist orageo:hasExactGeometry ?cgeom 
   FILTER (ogcf:sfEquals(?cgeom, 
             "Polygon((-83.6 34.1, -83.2 34.1, -83.2 34.5, 
                       -83.6 34.5, -83.6 34.1))"^^ogc:wktLiteral)) } '
,sem_models('gov_all_vm'), null, 
,sem_aliases(
   sem_alias('usgovt','http://www.rdfabout.com/rdf/schema/usgovt/'),
   sem_alias('pol','http://www.rdfabout.com/rdf/schema/politico/')
   )
,null, null, null, ' ALLOW_DUP=T '));

Parent topic: SEM_MATCH Support for Spatial Queries

B.14 ogcf:sfIntersects

Format

ogcf:sfIntersects(geom1 : geomLiteral, geom2 : geomLiteral) : xsd:boolean

Description

Returns true if the two geometries are not disjoint as defined by the OGC Simple Features specification (OGC 06-103r3). Returns false otherwise.

Parameters

geom1

Geometry object. Specified as a query variable or a constant geomLiteral value.

geom2

Geometry object. Specified as a query variable or a constant geomLiteral value.

Usage Notes

When invoking this function with a query variable and a constant geometry, always use the query variable as the first parameter and the constant geometry as the second parameter.

For best performance, geom1 should be a local variable (that is, a variable that appears in the basic graph pattern that contains the ogcf:sfIntersects spatial filter).

It is recommended to use a LEADING(?var) HINT0 hint when the query involves a restrictive ogcf:sfIntersects spatial filter on ?var.

See Spatial Support for information about representing , indexing, and querying spatial data in RDF.

See also the OGC GeoSPARQL specification.

Example

The following example finds U.S. Congressional district polygons that intersect a constant polygon.

SELECT name, cdist
FROM table(sem_match(
'{ # HINT0={LEADING(?cgeom)}
   ?person usgovt:name ?name .
   ?person pol:hasRole ?role .
   ?role pol:forOffice ?office .
   ?office pol:represents ?cdist .
   ?cdist orageo:hasExactGeometry ?cgeom 
   FILTER (ogcf:sfIntersects(?cgeom, 
             "Polygon((-83.6 34.1, -83.2 34.1, -83.2 34.5, 
                       -83.6 34.5, -83.6 34.1))"^^ogc:wktLiteral)) } '
,sem_models('gov_all_vm'), null, 
,sem_aliases(
   sem_alias('usgovt','http://www.rdfabout.com/rdf/schema/usgovt/'),
   sem_alias('pol','http://www.rdfabout.com/rdf/schema/politico/')
   )
,null, null, null, ' ALLOW_DUP=T '));

Parent topic: SEM_MATCH Support for Spatial Queries

B.15 ogcf:sfOverlaps

Format

ogcf:sfOverlaps(geom1 : geomLiteral, geom2 : geomLiteral) : xsd:boolean

Description

Returns true if geom1 spatially overlaps geom2 as defined by the OGC Simple Features specification (OGC 06-103r3). Returns false otherwise.

Parameters

geom1

Geometry object. Specified as a query variable or a constant geomLiteral value.

geom2

Geometry object. Specified as a query variable or a constant geomLiteral value.

Usage Notes

When invoking this function with a query variable and a constant geometry, always use the query variable as the first parameter and the constant geometry as the second parameter.

For best performance, geom1 should be a local variable (that is, a variable that appears in the basic graph pattern that contains the ogcf:sfOverlaps spatial filter).

It is recommended to use a LEADING(?var) HINT0 hint when the query involves a restrictive ogcf:sfOverlaps spatial filter on ?var.

See Spatial Support for information about representing , indexing, and querying spatial data in RDF.

See also the OGC GeoSPARQL specification.

Example

The following example finds U.S. Congressional district polygons that spatially overlap a constant polygon.

SELECT name, cdist
FROM table(sem_match(
'{ # HINT0={LEADING(?cgeom)}
   ?person usgovt:name ?name .
   ?person pol:hasRole ?role .
   ?role pol:forOffice ?office .
   ?office pol:represents ?cdist .
   ?cdist orageo:hasExactGeometry ?cgeom 
   FILTER (ogcf:sfOverlaps(?cgeom, 
             "Polygon((-83.6 34.1, -83.2 34.1, -83.2 34.5, 
                       -83.6 34.5, -83.6 34.1))"^^ogc:wktLiteral)) } '
,sem_models('gov_all_vm'), null, 
,sem_aliases(
   sem_alias('usgovt','http://www.rdfabout.com/rdf/schema/usgovt/'),
   sem_alias('pol','http://www.rdfabout.com/rdf/schema/politico/')
   )
,null, null, null, ' ALLOW_DUP=T '));

Parent topic: SEM_MATCH Support for Spatial Queries

B.16 ogcf:sfTouches

Format

ogcf:sfTouches(geom1 : geomLiteral, geom2 : geomLiteral) : xsd:boolean

Description

Returns true if the two geometries spatially touch as defined by the OGC Simple Features specification (OGC 06-103r3). Returns false otherwise.

Parameters

geom1

Geometry object. Specified as a query variable or a constant geomLiteral value.

geom2

Geometry object. Specified as a query variable or a constant geomLiteral value.

Usage Notes

When invoking this function with a query variable and a constant geometry, always use the query variable as the first parameter and the constant geometry as the second parameter.

For best performance, geom1 should be a local variable (that is, a variable that appears in the basic graph pattern that contains the ogcf:sfTouches spatial filter).

It is recommended to use a LEADING(?var) HINT0 hint when the query involves a restrictive ogcf:sfTouches spatial filter on ?var.

See Spatial Support for information about representing , indexing, and querying spatial data in RDF.

See also the OGC GeoSPARQL specification.

Example

The following example finds U.S. Congressional district polygons that spatially touch a constant polygon.

SELECT name, cdist
FROM table(sem_match(
'{ # HINT0={LEADING(?cgeom)}
   ?person usgovt:name ?name .
   ?person pol:hasRole ?role .
   ?role pol:forOffice ?office .
   ?office pol:represents ?cdist .
   ?cdist orageo:hasExactGeometry ?cgeom 
   FILTER (ogcf:sfTouches(?cgeom, 
             "Polygon((-83.6 34.1, -83.2 34.1, -83.2 34.5, 
                       -83.6 34.5, -83.6 34.1))"^^ogc:wktLiteral)) } '
,sem_models('gov_all_vm'), null, 
,sem_aliases(
   sem_alias('usgovt','http://www.rdfabout.com/rdf/schema/usgovt/'),
   sem_alias('pol','http://www.rdfabout.com/rdf/schema/politico/')
   )
,null, null, null, ' ALLOW_DUP=T '));

Parent topic: SEM_MATCH Support for Spatial Queries

B.17 ogcf:sfWithin

Format

ogcf:sfWithin(geom1 : geomLiteral, geom2 : geomLiteral) : xsd:boolean

Description

Returns true if geom1 is spatially within geom2 as defined by the OGC Simple Features specification (OGC 06-103r3). Returns false otherwise.

Parameters

geom1

Geometry object. Specified as a query variable or a constant geomLiteral value.

geom2

Geometry object. Specified as a query variable or a constant geomLiteral value.

Usage Notes

When invoking this function with a query variable and a constant geometry, always use the query variable as the first parameter and the constant geometry as the second parameter.

For best performance, geom1 should be a local variable (that is, a variable that appears in the basic graph pattern that contains the ogcf:sfWithin spatial filter).

It is recommended to use a LEADING(?var) HINT0 hint when the query involves a restrictive ogcf:sfWithin spatial filter on ?var.

See Spatial Support for information about representing , indexing, and querying spatial data in RDF.

See also the OGC GeoSPARQL specification.

Example

The following example finds U.S. Congressional district polygons that are spatially within a constant polygon.

SELECT name, cdist
FROM table(sem_match(
'{ # HINT0={LEADING(?cgeom)}
   ?person usgovt:name ?name .
   ?person pol:hasRole ?role .
   ?role pol:forOffice ?office .
   ?office pol:represents ?cdist .
   ?cdist orageo:hasExactGeometry ?cgeom 
   FILTER (ogcf:sfWithin(?cgeom, 
             "Polygon((-83.6 34.1, -83.2 34.1, -83.2 34.5, 
                       -83.6 34.5, -83.6 34.1))"^^ogc:wktLiteral)) } '
,sem_models('gov_all_vm'), null, 
,sem_aliases(
   sem_alias('usgovt','http://www.rdfabout.com/rdf/schema/usgovt/'),
   sem_alias('pol','http://www.rdfabout.com/rdf/schema/politico/')
   )
,null, null, null, ' ALLOW_DUP=T '));

Parent topic: SEM_MATCH Support for Spatial Queries

B.18 ogcf:symDifference

Format

ogcf:symDifference(geom1 : geomLiteral, geom2 : geomLiteral) : ogc:wktLiteral

Description

Returns a geometry object that is the topological symmetric difference (XOR operation) of geom1 and geom2.

Parameters

geom1

Geometry object. Specified as a query variable or a constant geomLiteral value.

geom2

Geometry object. Specified as a query variable or a constant geomLiteral value.

Usage Notes

See Spatial Support for information about representing , indexing, and querying spatial data in RDF.

See also the OGC GeoSPARQL specification.

Example

The following example finds the U.S. Congressional district polygons that are within a 100 kilometer buffer around a specified point.

SELECT name, cdist
FROM table(sem_match(
'{ ?person usgovt:name ?name .
   ?person pol:hasRole ?role .
   ?role pol:forOffice ?office .
   ?office pol:represents ?cdist .
   ?cdist orageo:hasExactGeometry ?cgeom 
   FILTER (ogcf:sfWithin(orageo:centroid(?cgeom), 
      ogcf:symDifference("Polygon((-83.6 34.1, -83.2 34.1, -83.2 34.5, 
                          -83.6 34.5, -83.6 34.1))"^^ogc:wktLiteral,
                          "Polygon((-83.2 34.3, -83.0 34.3, -83.0 34.5, 
                          -83.2 34.5, -83.2 34.3))"^^ogc:wktLiteral))) } '
,sem_models('gov_all_vm'), null, 
,sem_aliases(
   sem_alias('usgovt','http://www.rdfabout.com/rdf/schema/usgovt/'),
   sem_alias('pol','http://www.rdfabout.com/rdf/schema/politico/')
   )
,null, null, null, ' ALLOW_DUP=T '));

Parent topic: SEM_MATCH Support for Spatial Queries

B.19 ogcf:union

Format

ogcf:union(geom1 : geomLiteral, geom2 : geomLiteral) : ogc:wktLiteral

Description

Returns a geometry object that is the topological union (OR operation) of geom1 and geom2.

Parameters

geom1

Geometry object. Specified as a query variable or a constant geomLiteral value.

geom2

Geometry object. Specified as a query variable or a constant geomLiteral value.

Usage Notes

See Spatial Support for information about representing , indexing, and querying spatial data in RDF.

See also the OGC GeoSPARQL specification.

Example

The following example finds the U.S. Congressional district polygons whose centroid is within the union of two specified polygons.

SELECT name, cdist
FROM table(sem_match(
'{ ?person usgovt:name ?name .
   ?person pol:hasRole ?role .
   ?role pol:forOffice ?office .
   ?office pol:represents ?cdist .
   ?cdist orageo:hasExactGeometry ?cgeom 
   FILTER (ogcf:sfWithin(orageo:centroid(?cgeom), 
        ogcf:union("Polygon((-83.6 34.1, -83.2 34.1, -83.2 34.5, 
                    -83.6 34.5, -83.6 34.1))"^^ogc:wktLiteral,
                   "Polygon((-83.2 34.3, -83.0 34.3, -83.0 34.5, 
                    -83.2 34.5, -83.2 34.3))"^^ogc:wktLiteral))) } '
,sem_models('gov_all_vm'), null, 
,sem_aliases(
   sem_alias('usgovt','http://www.rdfabout.com/rdf/schema/usgovt/'),
   sem_alias('pol','http://www.rdfabout.com/rdf/schema/politico/')
   )
,null, null, null, ' ALLOW_DUP=T '));

Parent topic: SEM_MATCH Support for Spatial Queries

B.20 orageo:aggrCentroid

Format

orageo:aggrCentroid(geom : geomLiteral) : ogc:wktLiteral

Description

Returns a geometry literal that is the centroid of the group of specified geometry objects. (The centroid is also known as the "center of gravity.")

Parameters

geom

Geometry objects. Specified as a query variable.

Usage Notes

See Spatial Support for information about representing, indexing, and querying spatial data in RDF.

See also the SDO_AGGR_CENTROID function in Oracle Spatial and Graph Developer's Guide.

Example

The following example finds the centroid of all the U.S. Congressional district polygons.

SELECT centroid
FROM table(sem_match(
'select (orageo:aggrCentroid(?cgeom) as ?centroid)
 {?cdist orageo:hasExactGeometry ?cgeom } '
,sem_models('gov_all_vm'), null 
,sem_aliases(
   sem_alias('usgovt','http://www.rdfabout.com/rdf/schema/usgovt/'),
   sem_alias('pol','http://www.rdfabout.com/rdf/schema/politico/'))
,null, null, ' ALLOW_DUP=T '));

Parent topic: SEM_MATCH Support for Spatial Queries

B.21 orageo:aggrConvexHull

Format

orageo:aggrConvexhull(geom : geomLiteral) : ogc:wktLiteral

Description

Returns a geometry literal that is the convex hull of the group of specified geometry objects.. (The convex hull is a simple convex polygon that, for this funciton, completely encloses the group of geometry objects, using as few straight-line sides as possible to create the smallest polygon that completely encloses the geometry objects.)

Parameters

geom

Geometry objects. Specified as a query variable.

Usage Notes

See Spatial Support for information about representing, indexing, and querying spatial data in RDF.

See also the SDO_AGGR_CONVEXHULL function in Oracle Spatial and Graph Developer's Guide.

Example

The following example finds the convex hull of all the U.S. Congressional district polygons.

SELECT chull
FROM table(sem_match(
'select (orageo:aggrConvexhull(?cgeom) as ?chull)
 { 
   ?cdist orageo:hasExactGeometry ?cgeom } '
,sem_models('gov_all_vm'), null 
,sem_aliases(
   sem_alias('usgovt','http://www.rdfabout.com/rdf/schema/usgovt/'),
   sem_alias('pol','http://www.rdfabout.com/rdf/schema/politico/'))
,null, null, ' ALLOW_DUP=T '));

Parent topic: SEM_MATCH Support for Spatial Queries

B.22 orageo:aggrMBR

Format

orageo:aggrMBR(geom : geomLiteral) : ogc:wktLiteral

Description

Returns a geometry literal that is the minimum bounding rectangle (MBR) of the group of specified geometry objects.

Parameters

geom

Geometry objects. Specified as a query variable.

Usage Notes

See Spatial Support for information about representing, indexing, and querying spatial data in RDF.

See also the SDO_AGGR_MBR function in Oracle Spatial and Graph Developer's Guide.

Example

The following example finds the MBR of all the U.S. Congressional district polygons.

SELECT mbr
FROM table(sem_match(
'select (orageo:aggrMBR(?cgeom) as ?mbr)
 { 
   ?cdist orageo:hasExactGeometry ?cgeom } '
,sem_models('gov_all_vm'), null 
,sem_aliases(
   sem_alias('usgovt','http://www.rdfabout.com/rdf/schema/usgovt/'),
   sem_alias('pol','http://www.rdfabout.com/rdf/schema/politico/'))
,null, null, ' ALLOW_DUP=T '));

Parent topic: SEM_MATCH Support for Spatial Queries

B.23 orageo:aggrUnion

Format

orageo:aggrUnion(geom : geomLiteral) : ogc:wktLiteral

Description

Returns a geometry literal that is the topological union of the group of specified geometry objects.

Parameters

geom

Geometry objects. Specified as a query variable.

Usage Notes

See Spatial Support for information about representing, indexing, and querying spatial data in RDF.

See also the SDO_GEOM.SDO_UNION function in Oracle Spatial and Graph Developer's Guide.

Example

The following example finds the union of all the U.S. Congressional district polygons.

SELECT u
FROM table(sem_match(
'select (orageo:aggrUnion(?cgeom) as ?u)
 { 
   ?cdist orageo:hasExactGeometry ?cgeom } '
,sem_models('gov_all_vm'), null 
,sem_aliases(
   sem_alias('usgovt','http://www.rdfabout.com/rdf/schema/usgovt/'),
   sem_alias('pol','http://www.rdfabout.com/rdf/schema/politico/'))
,null, null, ' ALLOW_DUP=T '));

Parent topic: SEM_MATCH Support for Spatial Queries

B.24 orageo:area

Format

orageo:area(geom1 : geomLiteral, unit : Literal) : xsd:decimal

Description

Returns the area of geom1 in terms of the specified unit of measure.

Parameters

geom1

Geometry object. Specified as a query variable or a constant geomLiteral value.

unit

Unit of measurement: a quoted string with an SDO_UNIT value from the MDSYS.SDO_DIST_UNITS table (for example, "unit=SQ_KM"). See the section about unit of measurement support in Oracle Spatial and Graph Developer's Guide for more information about unit of measurement specification.

Usage Notes

See Spatial Support for information about representing , indexing, and querying spatial data in RDF.

See also the SDO_GEOM.SDO_AREA function in Oracle Spatial and Graph Developer's Guide.

Example

The following example finds the U.S. Congressional district polygons with areas greater than 10,000 square kilometers.

SELECT name, cdist
FROM table(sem_match(
'{ ?person usgovt:name ?name .
   ?person pol:hasRole ?role .
   ?role pol:forOffice ?office .
   ?office pol:represents ?cdist .
   ?cdist orageo:hasExactGeometry ?cgeom 
   FILTER (orageo:area(?cgeom, "unit=SQ_KM") > 10000) }'
,sem_models('gov_all_vm'), null, 
,sem_aliases(
   sem_alias('usgovt','http://www.rdfabout.com/rdf/schema/usgovt/'),
   sem_alias('pol','http://www.rdfabout.com/rdf/schema/politico/'))
,null, null, null, ' ALLOW_DUP=T '));

Parent topic: SEM_MATCH Support for Spatial Queries

B.25 orageo:buffer

Format

orageo:buffer(geom1 : geomLiteral, distance : xsd:decimal, unit : Literal) : geomLiteral

Description

Returns a buffer polygon at a specified distance around or inside a geometry.

Parameters

geom1

Geometry object. Specified as a query variable or a constant geomLiteral value.

distance

Distance value. Distance value. If the value is positive, the buffer is generated around geom1; if the value is negative (valid only for polygons), the buffer is generated inside geom1.

unit

Unit of measurement: a quoted string with an SDO_UNIT value from the MDSYS.SDO_DIST_UNITS table (for example, "unit=KM"). See the section about unit of measurement support in Oracle Spatial and Graph Developer's Guide for more information about unit of measurement specification.

Usage Notes

See Spatial Support for information about representing , indexing, and querying spatial data in RDF.

See also the SDO_GEOM.SDO_BUFFER function in Oracle Spatial and Graph Developer's Guide.

Example

The following example finds the U.S. Congressional district polygons that are completely inside a 100 kilometer buffer around a specified point.

SELECT name, cdist
FROM table(sem_match(
'{ # HINT0={LEADING(?cgeom)}
   ?person usgovt:name ?name .
   ?person pol:hasRole ?role .
   ?role pol:forOffice ?office .
   ?office pol:represents ?cdist .
   ?cdist orageo:hasExactGeometry ?cgeom 
   FILTER (
     orageo:relate(?cgeom, 
       orageo:buffer("POINT(-71.46444 42.7575)"^^orageo:WKTLiteral,
                     100, "unit=KM"),
      "mask=inside")) }'
,sem_models('gov_all_vm'), null, 
,sem_aliases(
   sem_alias('usgovt','http://www.rdfabout.com/rdf/schema/usgovt/'),
   sem_alias('pol','http://www.rdfabout.com/rdf/schema/politico/'))
,null, null, null, ' ALLOW_DUP=T '));

Parent topic: SEM_MATCH Support for Spatial Queries

B.26 orageo:centroid

Format

orageo:centroid(geom1 : geomLiteral) : geomLiteral

Description

Returns a point geometry that is the centroid of geom1. (The centroid is also known as the "center of gravity.")

Parameters

geom1

Geometry object. Specified as a query variable or a constant geomLiteral value.

Usage Notes

For an input geometry consisting of multiple objects, the result is weighted by the area of each polygon in the geometry objects. If the geometry objects are a mixture of polygons and points, the points are not used in the calculation of the centroid. If the geometry objects are all points, the points have equal weight.

See Spatial Support for information about representing , indexing, and querying spatial data in RDF.

See also the SDO_GEOM.SDO_CENTROID function in Oracle Spatial and Graph Developer's Guide.

Example

The following example finds the U.S. Congressional district polygons with centroids within 200 kilometers of a specified point.

SELECT name, cdist
FROM table(sem_match(
'{ ?person usgovt:name ?name .
   ?person pol:hasRole ?role .
   ?role pol:forOffice ?office .
   ?office pol:represents ?cdist .
   ?cdist orageo:hasExactGeometry ?cgeom 
   FILTER (orageo:withinDistance(orageo:centroid(?cgeom), 
      "POINT(-71.46444 42.7575)"^^orageo:WKTLiteral,
      "distance=200 unit=KM")) } '
,sem_models('gov_all_vm'), null, 
,sem_aliases(
   sem_alias('usgovt','http://www.rdfabout.com/rdf/schema/usgovt/'),
   sem_alias('pol','http://www.rdfabout.com/rdf/schema/politico/'))
,null, null, null, ' ALLOW_DUP=T '));

Parent topic: SEM_MATCH Support for Spatial Queries

B.27 orageo:convexHull

Format

orageo:convexHull(geom1 : geomLiteral) : geomLiteral

Description

Returns a polygon-type object that represents the convex hull of geom1. (The convex hull is a simple convex polygon that completely encloses the geometry object, using as few straight-line sides as possible to create the smallest polygon that completely encloses the geometry object.)

Parameters

geom1

Geometry object. Specified as a query variable or a constant geomLiteral value.

Usage Notes

A convex hull is a convenient way to get an approximation of a complex geometry object.

See Spatial Support for information about representing , indexing, and querying spatial data in RDF.

See also the SDO_GEOM.SDO_CONVEX_HULL function in Oracle Spatial and Graph Developer's Guide.

Example

The following example finds the U.S. Congressional district polygons whose convex hull contains a specified point.

SELECT name, cdist
FROM table(sem_match(
'{ ?person usgovt:name ?name .
   ?person pol:hasRole ?role .
   ?role pol:forOffice ?office .
   ?office pol:represents ?cdist .
   ?cdist orageo:hasExactGeometry ?cgeom 
   FILTER (orageo:relate(orageo:convexHull(?cgeom), 
      "POINT(-71.46444 42.7575)"^^orageo:WKTLiteral,
      "mask=contains")) } '
,sem_models('gov_all_vm'), null, 
,sem_aliases(
   sem_alias('usgovt','http://www.rdfabout.com/rdf/schema/usgovt/'),
   sem_alias('pol','http://www.rdfabout.com/rdf/schema/politico/'))
,null, null, null, ' ALLOW_DUP=T '));

Parent topic: SEM_MATCH Support for Spatial Queries

B.28 orageo:difference

Format

orageo:difference(geom1 : geomLiteral, geom2 : geomLiteral) : geomLiteral

Description

Returns a geometry object that is the topological difference (MINUS operation) of geom1 and geom2.

Parameters

geom1

Geometry object. Specified as a query variable or a constant geomLiteral value.

geom2

Geometry object. Specified as a query variable or a constant geomLiteral value.

Usage Notes

See Spatial Support for information about representing , indexing, and querying spatial data in RDF.

See also the SDO_GEOM.SDO_UNION function in Oracle Spatial and Graph Developer's Guide.

Example

The following example finds the U.S. Congressional district polygons whose centroid is inside the difference of two specified polygons.

SELECT name, cdist
FROM table(sem_match(
'{ ?person usgovt:name ?name .
   ?person pol:hasRole ?role .
   ?role pol:forOffice ?office .
   ?office pol:represents ?cdist .
   ?cdist orageo:hasExactGeometry ?cgeom 
   FILTER (orageo:relate(orageo:centroid(?cgeom), 
      orageo:difference("Polygon((-83.6 34.1, -83.2 34.1, -83.2 34.5, 
                         -83.6 34.5, -83.6 34.1))"^^orageo:WKTLiteral,
                        "Polygon((-83.2 34.3, -83.0 34.3, -83.0 34.5, 
                         -83.2 34.5, -83.2 34.3))"^^orageo:WKTLiteral),
      "mask=inside")) } '
,sem_models('gov_all_vm'), null, 
,sem_aliases(
   sem_alias('usgovt','http://www.rdfabout.com/rdf/schema/usgovt/'),
   sem_alias('pol','http://www.rdfabout.com/rdf/schema/politico/'))
,null, null, null, ' ALLOW_DUP=T '));

Parent topic: SEM_MATCH Support for Spatial Queries

B.29 orageo:distance

Format

orageo:distance(geom1 : geomLiteral, geom2 : geomLiteral, unit : Literal) : xsd:decimal

Description

Returns the distance between the nearest pair of points or segments of geom1 and geom2 in terms of the specified unit of measure.

Parameters

geom1

Geometry object. Specified as a query variable or a constant geomLiteral value.

geom2

Geometry object. Specified as a query variable or a constant geomLiteral value.

unit

Unit of measurement: a quoted string with an SDO_UNIT value from the MDSYS.SDO_DIST_UNITS table (for example, "unit=KM"). See the section about unit of measurement support in Oracle Spatial and Graph Developer's Guide for more information about unit of measurement specification.

Usage Notes

Use orageo:withinDistance instead of orageo:distance whenever possible, because orageo:withinDistance has a more efficient index-based implementation.

See Spatial Support for information about representing , indexing, and querying spatial data in RDF.

See also the SDO_GEOM.SDO_DISTANCE function in Oracle Spatial and Graph Developer's Guide.

Example

The following example finds the ten nearest U.S. Congressional districts to a specified point and orders them by distance from the point.

SELECT name, cdist
FROM table(sem_match(
'SELECT ?name ?cdist
 WHERE
 { # HINT0={LEADING(?cgeom)}
   ?person usgovt:name ?name .
   ?person pol:hasRole ?role .
   ?role pol:forOffice ?office .
   ?office pol:represents ?cdist .
   ?cdist orageo:hasExactGeometry ?cgeom 
   FILTER (orageo:nearestNeighbor(?cgeom, 
      "POINT(-71.46444 42.7575)"^^orageo:WKTLiteral,
      "sdo_num_res=10")) }
 ORDER BY ASC(orageo:distance(?cgeom,
                "POINT(-71.46444 42.7575)"^^orageo:WKTLiteral,
                "unit=KM"))'
,sem_models('gov_all_vm'), null, 
,sem_aliases(
   sem_alias('usgovt','http://www.rdfabout.com/rdf/schema/usgovt/'),
   sem_alias('pol','http://www.rdfabout.com/rdf/schema/politico/'))
,null, null, null, ' ALLOW_DUP=T '))
ORDER BY sem$rownum;

Parent topic: SEM_MATCH Support for Spatial Queries

B.30 orageo:getSRID

Format

orageo:getSRID(geom : geomLiteral) : xsd:anyURI

Description

Returns the oracle spatial reference system (SRID) URI for geom.

Parameters

geom

Geometry object. Specified as a query variable or a constant geomLiteral value.

Usage Notes

See Spatial Support for information about representing, indexing, and querying spatial data in RDF.

Example

The following example finds spatial reference system URIs for U.S. Congressional district polygons.

SELECT csrid
FROM table(sem_match(
'SELECT (orageo:getSRID(?cgeom) AS ?csrid)
 WHERE
 { ?person usgovt:name ?name .
   ?person pol:hasRole ?role .
   ?role pol:forOffice ?office .
   ?office pol:represents ?cdist .
   ?cdist orageo:hasExactGeometry ?cgeom }'
,sem_models('gov_all_vm'), null 
,sem_aliases(
   sem_alias('usgovt','http://www.rdfabout.com/rdf/schema/usgovt/'),
   sem_alias('pol','http://www.rdfabout.com/rdf/schema/politico/')
   )
,null, null, ' ALLOW_DUP=T '));

Parent topic: SEM_MATCH Support for Spatial Queries

B.31 orageo:intersection

Format

orageo:intersection(geom1 : geomLiteral, geom2 : geomLiteral) : geomLiteral

Description

Returns a geometry object that is the topological intersection (AND operation) of geom1 and geom2.

Parameters

geom1

Geometry object. Specified as a query variable or a constant geomLiteral value.

geom2

Geometry object. Specified as a query variable or a constant geomLiteral value.

Usage Notes

See Spatial Support for information about representing , indexing, and querying spatial data in RDF.

See also the SDO_GEOM.SDO_INTERSECTION function in Oracle Spatial and Graph Developer's Guide.

Example

The following example finds the U.S. Congressional district polygons whose centroid is inside the intersection of two specified polygons.

SELECT name, cdist
FROM table(sem_match(
'{ ?person usgovt:name ?name .
   ?person pol:hasRole ?role .
   ?role pol:forOffice ?office .
   ?office pol:represents ?cdist .
   ?cdist orageo:hasExactGeometry ?cgeom 
   FILTER (orageo:relate(orageo:centroid(?cgeom), 
      orageo:intersection("Polygon((-83.6 34.1, -83.2 34.1, -83.2 34.5, 
                           -83.6 34.5, -83.6 34.1))"^^orageo:WKTLiteral,
                          "Polygon((-83.2 34.3, -83.0 34.3, -83.0 34.5, 
                           -83.2 34.5, -83.2 34.3))"^^orageo:WKTLiteral),
      "mask=inside")) } '
,sem_models('gov_all_vm'), null, 
,sem_aliases(
   sem_alias('usgovt','http://www.rdfabout.com/rdf/schema/usgovt/'),
   sem_alias('pol','http://www.rdfabout.com/rdf/schema/politico/'))
,null, null, null, ' ALLOW_DUP=T '));

Parent topic: SEM_MATCH Support for Spatial Queries

B.32 orageo:length

Format

orageo:length(geom1 : geomLiteral, unit : Literal) : xsd:decimal

Description

Returns the length or perimeter of geom1 in terms of the specified unit of measure.

Parameters

geom1

Geometry object. Specified as a query variable or a constant geomLiteral value.

unit

Unit of measurement: a quoted string with an SDO_UNIT value from the MDSYS.SDO_DIST_UNITS table (for example, "unit=KM"). See the section about unit of measurement support in Oracle Spatial and Graph Developer's Guide for more information about unit of measurement specification.

Usage Notes

See Spatial Support for information about representing , indexing, and querying spatial data in RDF.

See also the SDO_GEOM.SDO_LENGTH function in Oracle Spatial and Graph Developer's Guide.

Example

The following example finds the U.S. Congressional district polygons with lengths (perimeters) greater than 1000 kilometers.

SELECT name, cdist
FROM table(sem_match(
'{ ?person usgovt:name ?name .
   ?person pol:hasRole ?role .
   ?role pol:forOffice ?office .
   ?office pol:represents ?cdist .
   ?cdist orageo:hasExactGeometry ?cgeom 
   FILTER (orageo:legnth(?cgeom, "unit=KM") > 1000) }'
,sem_models('gov_all_vm'), null, 
,sem_aliases(
   sem_alias('usgovt','http://www.rdfabout.com/rdf/schema/usgovt/'),
   sem_alias('pol','http://www.rdfabout.com/rdf/schema/politico/'))
,null, null, null, ' ALLOW_DUP=T '));

Parent topic: SEM_MATCH Support for Spatial Queries

B.33 orageo:mbr

Format

orageo:mbr(geom1 : geomLiteral) : geomLiteral

Description

Returns the minimum bounding rectangle of geom1, that is, the single rectangle that minimally encloses geom1.

Parameters

geom1

Geometry object. Specified as a query variable or a constant geomLiteral value.

Usage Notes

See Spatial Support for information about representing , indexing, and querying spatial data in RDF.

See also the SDO_GEOM.SDO_MBR function in Oracle Spatial and Graph Developer's Guide.

Example

The following example finds the U.S. Congressional district polygons whose minimum bounding rectangle contains a specified point.

SELECT name, cdist
FROM table(sem_match(
'{ ?person usgovt:name ?name .
   ?person pol:hasRole ?role .
   ?role pol:forOffice ?office .
   ?office pol:represents ?cdist .
   ?cdist orageo:hasExactGeometry ?cgeom 
   FILTER (orageo:relate(orageo:mbr(?cgeom), 
      "POINT(-71.46444 42.7575)"^^orageo:WKTLiteral,
      "mask=contains")) } '
,sem_models('gov_all_vm'), null, 
,sem_aliases(
   sem_alias('usgovt','http://www.rdfabout.com/rdf/schema/usgovt/'),
   sem_alias('pol','http://www.rdfabout.com/rdf/schema/politico/'))
,null, null, null, ' ALLOW_DUP=T '));

Parent topic: SEM_MATCH Support for Spatial Queries

B.34 orageo:nearestNeighbor

Format

orageo:nearestNeighbor(geom1:  geomLiteral, geom2 : geomLiteral, param : Literal) : xsd:boolean

Description

Returns true if geom1 is a nearest neighbor of geom2, where the size of the nearest neighbors set is specified by param; returns false otherwise.

Parameters

geom1

Geometry object. Specified as a query variable.

geom2

Geometry object. Specified as a query variable or a constant geomLiteral value.

param

Determines the behavior of the operator. See the Usage Notes for the available keyword-value pairs.

Usage Notes

In the param parameter, the available keyword-value pairs are:

  • distance=n specifies the maximum allowable distance for the nearest neighbor search.

  • sdo_num_res=n specifies the size of the set for the nearest neighbor search.

  • unit=unit specifies the unit of measurement to use with distance value. If you do not specify a value, the unit of measurement associated with the data is used.

geom1 must be a local variable (that is, a variable that appears in the basic graph pattern that contains the orageo:nearestNeighbor spatial filter).

It is a good idea to use a 'LEADING(?var)' HINT0 hint when your query involves a restrictive orageo:relate spatial filter on ?var.

See Spatial Support for information about representing , indexing, and querying spatial data in RDF.

See also the SDO_NN operator in Oracle Spatial and Graph Developer's Guide.

Example

The following example finds the ten nearest U.S. Congressional districts to a specified point.

SELECT name, cdist
FROM table(sem_match(
'{ # HINT0={LEADING(?cgeom)}
   ?person usgovt:name ?name .
   ?person pol:hasRole ?role .
   ?role pol:forOffice ?office .
   ?office pol:represents ?cdist .
   ?cdist orageo:hasExactGeometry ?cgeom 
   FILTER (orageo:nearestNeighbor(?cgeom, 
      "POINT(-71.46444 42.7575)"^^orageo:WKTLiteral,
      "sdo_num_res=10")) } '
,sem_models('gov_all_vm'), null, 
,sem_aliases(
   sem_alias('usgovt','http://www.rdfabout.com/rdf/schema/usgovt/'),
   sem_alias('pol','http://www.rdfabout.com/rdf/schema/politico/'))
,null, null, null, ' ALLOW_DUP=T '));

Parent topic: SEM_MATCH Support for Spatial Queries

B.35 orageo:relate

Format

orageo:relate(geom1:  geomLiteral, geom2 : geomLiteral, param : Literal) : xsd:boolean

Description

Returns true if geom1 and geom2 satisfy the topological spatial relation specified by the param parameter; returns false otherwise.

Parameters

geom1

Geometry object. Specified as a query variable or a constant geomLiteral value.

geom2

Geometry object. Specified as a query variable or a constant geomLiteral value.

param

Specifies a list of mask relationships to check. See the list of keywords in the Usage Notes.

Usage Notes

The following param values (mask relationships) can be tested:

  • ANYINTERACT: Returns TRUE if the objects are not disjoint.

  • CONTAINS: Returns CONTAINS if the second object is entirely within the first object and the object boundaries do not touch; otherwise, returns FALSE.

  • COVEREDBY: Returns COVEREDBY if the first object is entirely within the second object and the object boundaries touch at one or more points; otherwise, returns FALSE.

  • COVERS: Returns COVERS if the second object is entirely within the first object and the boundaries touch in one or more places; otherwise, returns FALSE.

  • DISJOINT: Returns DISJOINT if the objects have no common boundary or interior points; otherwise, returns FALSE.

  • EQUAL: Returns EQUAL if the objects share every point of their boundaries and interior, including any holes in the objects; otherwise, returns FALSE.

  • INSIDE: Returns INSIDE if the first object is entirely within the second object and the object boundaries do not touch; otherwise, returns FALSE.

  • ON: Returns ON if the boundary and interior of a line (the first object) is completely on the boundary of a polygon (the second object); otherwise, returns FALSE.

  • OVERLAPBDYDISJOINT: Returns OVERLAPBDYDISJOINT if the objects overlap, but their boundaries do not interact; otherwise, returns FALSE.

  • OVERLAPBDYINTERSECT: Returns OVERLAPBDYINTERSECT if the objects overlap, and their boundaries intersect in one or more places; otherwise, returns FALSE.

  • TOUCH: Returns TOUCH if the two objects share a common boundary point, but no interior points; otherwise, returns FALSE.

Values for param can be combined using the logical Boolean operator OR. For example, 'INSIDE + TOUCH' returns INSIDE+TOUCH if the relationship between the geometries is INSIDE or TOUCH or both INSIDE and TOUCH; it returns FALSE if the relationship between the geometries is neither INSIDE nor TOUCH.

When invoking orageo:relate with a query variable and a constant geometry, always use the query variable as the first parameter and the constant geometry as the second parameter.

For best performance, geom1 should be a local variable (that is, a variable that appears in the basic graph pattern that contains the orageo:relate spatial filter).

It is a good idea to use a 'LEADING(?var)' HINT0 hint when your query involves a restrictive orageo:relate spatial filter on ?var.

See Spatial Support for information about representing , indexing, and querying spatial data in RDF.

See also the SDO_RELATE operator in Oracle Spatial and Graph Developer's Guide.

Example

The following example finds the U.S. Congressional district that contains a specified point.

SELECT name, cdist
FROM table(sem_match(
'{ # HINT0={LEADING(?cgeom)}
   ?person usgovt:name ?name .
   ?person pol:hasRole ?role .
   ?role pol:forOffice ?office .
   ?office pol:represents ?cdist .
   ?cdist orageo:hasExactGeometry ?cgeom 
   FILTER (orageo:relate(?cgeom, 
      "POINT(-71.46444 42.7575)"^^orageo:WKTLiteral,
      "mask=contains")) } '
,sem_models('gov_all_vm'), null, 
,sem_aliases(
   sem_alias('usgovt','http://www.rdfabout.com/rdf/schema/usgovt/'),
   sem_alias('pol','http://www.rdfabout.com/rdf/schema/politico/'))
,null, null, null, ' ALLOW_DUP=T '
));

Parent topic: SEM_MATCH Support for Spatial Queries

B.36 orageo:sdoDistJoin

Format

orageo:sdoDistJoin(geom1 : geomLiteral, geom2 : geomLiteral, param : Literal) : xsd:boolean

Description

Performs a spatial join based on distance between two geometries. Returns true if the distance between geom1 and geom2 is within the given value specified in param; returns false otherwise.

Parameters

geom1

Geometry object. Specified as a query variable or a constant geomLiteral value.

geom2

Geometry object. Specified as a query variable or a constant geomLiteral value.

param

Specifies a distance value and unit of measure to use for the distance-based spatial join. The distance value is added to the tolerance value of the associated spatial index. For example if "distance=100 and unit=m" is used with a tolerance value of 10 meters, then orageo:sdoDistJoin returns true if the distance between two geometries is no more than 110 meters.

Usage Notes

orageo:sdoDistJoin should be used when performing a distance-based spatial join between two large geometry collections. When performing a distance-based spatial join between one small geometry collection and one large geometry collection, invoking orageo:withinDistance with the small geometry collection as the first argument will usually give better performance than orageo:sdoDistJoin.

See Spatial Support for information about representing, indexing, and querying spatial data in RDF.

See also the SDO_JOIN operator in Oracle Spatial and Graph Developer's Guide.

Example

The following example finds pairs of U.S. Congressional district polygons that are within 100 meters of each other.

SELECT cdist1, cdist2
FROM table(sem_match(
'{ ?cdist1 orageo:hasExactGeometry ?cgeom1 .
   ?cdist2 orageo:hasExactGeometry ?cgeom2 
   FILTER (orageo:sdoDistJoin(?cgeom1, ?cgeom2, 
      "distance=100 unit=m")) } '
,sem_models('gov_all_vm'), null 
,sem_aliases(
   sem_alias('usgovt','http://www.rdfabout.com/rdf/schema/usgovt/'),
   sem_alias('pol','http://www.rdfabout.com/rdf/schema/politico/'))
,null, null, ' ALLOW_DUP=T '
));

Parent topic: SEM_MATCH Support for Spatial Queries

B.37 orageo:sdoJoin

Format

orageo:sdoJoin(geom1 : geomLiteral, geom2 : geomLiteral, param : Literal) : xsd:boolean

Description

Performs a spatial join based on one or more topological relationships. Returns true if geom1 and geom2 satisfy the spatial relationship specified by param; returns false otherwise.

Parameters

geom1

Geometry object. Specified as a query variable or a constant geomLiteral value.

geom2

Geometry object. Specified as a query variable or a constant geomLiteral value.

param

Specifies a list of mask relationships to check. The topological relationship of interest.Valid values are 'mask=<value>' where <value> is one or more of the mask values that are valid for the SDO_RELATE operator (TOUCH, OVERLAPBDYDISJOINT, OVERLAPBDYINTERSECT, EQUAL, INSIDE, COVEREDBY, CONTAINS, COVERS, ANYINTERACT, ON). Multiple masks are combined with the logical Boolean operator OR (for example, "mask=inside+touch").

Usage Notes

orageo:sdoJoin should be used when performing a spatial join between two large geometry collections. When performing a spatial join between one small geometry collection and one large geometry collection, invoking orageo:relate with the small geometry collection as the first argument will usually give better performance than orageo:sdoJoin.

See Spatial Support for information about representing, indexing, and querying spatial data in RDF.

See also the SDO_JOIN operator in Oracle Spatial and Graph Developer's Guide.

Example

The following example finds pairs of U.S. Congressional district polygons that have any spatial interaction.

SELECT cdist1, cdist2
FROM table(sem_match(
'{ ?cdist1 orageo:hasExactGeometry ?cgeom1 .
   ?cdist2 orageo:hasExactGeometry ?cgeom2 
   FILTER (orageo:sdoJoin(?cgeom1, ?cgeom2, 
      "mask=anyinteract")) } '
,sem_models('gov_all_vm'), null 
,sem_aliases(
   sem_alias('usgovt','http://www.rdfabout.com/rdf/schema/usgovt/'),
   sem_alias('pol','http://www.rdfabout.com/rdf/schema/politico/'))
,null, null, ' ALLOW_DUP=T '
));

Parent topic: SEM_MATCH Support for Spatial Queries

B.38 orageo:union

Format

orageo:union(geom1 : geomLiteral, geom2 : geomLiteral) : geomLiteral

Description

Returns a geometry object that is the topological union (OR operation) of geom1 and geom2.

Parameters

geom1

Geometry object. Specified as a query variable or a constant geomLiteral value.

geom2

Geometry object. Specified as a query variable or a constant geomLiteral value.

Usage Notes

See Spatial Support for information about representing , indexing, and querying spatial data in RDF.

See also the SDO_GEOM.SDO_UN ION function in Oracle Spatial and Graph Developer's Guide.

Example

The following example finds the U.S. Congressional district polygons whose centroid is inside the union of two specified polygons.

SELECT name, cdist
FROM table(sem_match(
'{ ?person usgovt:name ?name .
   ?person pol:hasRole ?role .
   ?role pol:forOffice ?office .
   ?office pol:represents ?cdist .
   ?cdist orageo:hasExactGeometry ?cgeom 
   FILTER (orageo:relate(orageo:centroid(?cgeom), 
      orageo:union("Polygon((-83.6 34.1, -83.2 34.1, -83.2 34.5, 
                    -83.6 34.5, -83.6 34.1))"^^orageo:WKTLiteral,
                   "Polygon((-83.2 34.3, -83.0 34.3, -83.0 34.5, 
                    -83.2 34.5, -83.2 34.3))"^^orageo:WKTLiteral),
      "mask=inside")) } '
,sem_models('gov_all_vm'), null, 
,sem_aliases(
   sem_alias('usgovt','http://www.rdfabout.com/rdf/schema/usgovt/'),
   sem_alias('pol','http://www.rdfabout.com/rdf/schema/politico/'))
,null, null, null, ' ALLOW_DUP=T '));

Parent topic: SEM_MATCH Support for Spatial Queries

B.39 orageo:withinDistance

Format

orageo:withinDistance(geom1 : geomLiteral, geom2 : geomLiteral, distance : xsd:decimal, unit : Literal) : xsd:boolean

Description

Returns true if the distance between geom1 and geom2 is less than or equal to distance when measured in unit; returns false otherwise.

Parameters

geom1

Geometry object. Specified as a query variable or a constant geomLiteral value.

geom2

Geometry object. Specified as a query variable or a constant geomLiteral value.

distance

Distance value.

unit

Unit of measurement: a quoted string with an SDO_UNIT value from the MDSYS.SDO_DIST_UNITS table (for example, "unit=KM"). See the section about unit of measurement support in Oracle Spatial and Graph Developer's Guide for more information about unit of measurement specification.

Usage Notes

When invoking this function with a query variable and a constant geometry, always use the query variable as the first parameter and the constant geometry as the second parameter.

For best performance, geom1 should be a local variable (that is, a variable that appears in the basic graph pattern that contains the orageo:withinDistance spatial filter).

It is a good idea to use a 'LEADING(?var)' HINT0 hint when your query involves a restrictive orageo:withinDistance spatial filter on ?var.

See Spatial Support for information about representing , indexing, and querying spatial data in RDF.

See also the SDO_WITHIN_DISTANCE operator in Oracle Spatial and Graph Developer's Guide.

Example

The following example finds the U.S. Congressional districts that are within 100 kilometers of a specified point.

SELECT name, cdist
FROM table(sem_match(
'{ # HINT0={LEADING(?cgeom)}
   ?person usgovt:name ?name .
   ?person pol:hasRole ?role .
   ?role pol:forOffice ?office .
   ?office pol:represents ?cdist .
   ?cdist orageo:hasExactGeometry ?cgeom 
   FILTER (orageo:withinDistance(?cgeom, 
      "POINT(-71.46444 42.7575)"^^orageo:WKTLiteral,
      100, "KM")) } '
,sem_models('gov_all_vm'), null, 
,sem_aliases(
   sem_alias('usgovt','http://www.rdfabout.com/rdf/schema/usgovt/'),
   sem_alias('pol','http://www.rdfabout.com/rdf/schema/politico/'))
,null, null, null, ' ALLOW_DUP=T '));

Parent topic: SEM_MATCH Support for Spatial Queries

B.40 orageo:xor

Format

orageo:xor(geom1 : geomLiteral, geom2 : geomLiteral) : geomLiteral

Description

Returns a geometry object that is the topological symmetric difference (XOR operation) of geom1 and geom2.

Parameters

geom1

Geometry object. Specified as a query variable or a constant geomLiteral value.

geom2

Geometry object. Specified as a query variable or a constant geomLiteral value.

Usage Notes

See Spatial Support for information about representing , indexing, and querying spatial data in RDF.

See also the SDO_GEOM.SDO_XOR function in Oracle Spatial and Graph Developer's Guide.

Example

The following example finds the U.S. Congressional district polygons whose centroid is inside the symmetric difference of two specified polygons.

SELECT name, cdist
FROM table(sem_match(
'{ ?person usgovt:name ?name .
   ?person pol:hasRole ?role .
   ?role pol:forOffice ?office .
   ?office pol:represents ?cdist .
   ?cdist orageo:hasExactGeometry ?cgeom 
   FILTER (orageo:relate(orageo:centroid(?cgeom), 
      orageo:xor("Polygon((-83.6 34.1, -83.2 34.1, -83.2 34.5, 
                  -83.6 34.5, -83.6 34.1))"^^orageo:WKTLiteral,
                 "Polygon((-83.2 34.3, -83.0 34.3, -83.0 34.5, 
                  -83.2 34.5, -83.2 34.3))"^^orageo:WKTLiteral),
      "mask=inside")) } '
,sem_models('gov_all_vm'), null, 
,sem_aliases(
   sem_alias('usgovt','http://www.rdfabout.com/rdf/schema/usgovt/'),
   sem_alias('pol','http://www.rdfabout.com/rdf/schema/politico/'))
,null, null, null, ' ALLOW_DUP=T '));

Parent topic: SEM_MATCH Support for Spatial Queries