Semantic Astronomy SeRQL^? Notes

SeRQL Examples for Practical Semantic Astronomy Workshop Hack-a-thon
Elizabeth Auden, AstroGrid / VOTech
11 February 2008

Semantic Astronomy Sesame Knowledge Base

• MSSL endpoint: http://msslxx.mssl.ucl.ac.uk:8080/sesame
• Knowledge base: MySQL RDFS TestDB^? Semantic Astronomy
• OpenRDF^? SeRQL^? guide: http://www.openrdf.org/doc/sesame/users/ch06.html
• OpenRDF^? SeRQL^? 1.1 query examples: http://www.openrdf.org/sesame/serql/serql-examples.html#string

All queries can be performed as user "anonymous" without being logged in. In the top menu bar next to "Read actions", click "SeRQL-S" and try out the following queries.

Example SeRQL^? queries

Queries about ontology classes

1. See all class names included with uploaded ontologies
   select C from {C} rdf:type {rdfs:Class}
2. Select all subclasses of "galaxy":
   SELECT * FROM {sub} rdfs:subClassOf {<http://www.ivoa.net/ontology/astronomy.owl#galaxy>}
3. Select all direct subclasses of "galaxy":
   SELECT * FROM {directSub} serql:directSubClassOf {<http://www.ivoa.net/ontology/astronomy.owl#galaxy>}

Basic data queries

1. Select all entries for a certain event type (e.g., supernova remnants)
   SELECT DISTINCT * FROM {C} ast:supernovaRemnant {} USING NAMESPACE ast = <http://archive.astro.umd.edu/ivoa-onto/src/main/resources/astronomy.owl>
   • Click the entry (e.g. http://msslxx.mssl.ucl.ac.uk:8080/sesame/m100.rdf) to see its statements in the format subject | predicate | object.
   • Other event types to query in place of ast:supernovaRemnant:
     • ast:activeGalacticNucleus
     • ast:galacticCluster
     • ast:galaxy
     • ast:globularCluster
     • ast:HeIiIonizationZone
     • ast:interactingGalaxy
     • ast:linerGalaxy
     • ast:openStarCluster
     • ast:planetaryNebula
     • ast:reflectionNebula
     • ast:SeyfertGalaxy
     • ast:starburstGalaxy
     • ast:starCluster
2. Select all properties and values from the RDF entry for M23:
   select * from {<http://msslxx.mssl.ucl.ac.uk:8080/sesame/m23.rdf>} p {value}
3. Select entries for all globularClusters:
   select globularCluster from {globularCluster} ast:globularCluster {} USING NAMESPACE ast = <http://archive.astro.umd.edu/ivoa-onto/src/main/resources/astronomy.owl>, ivoao = <http://archive.astro.umd.edu/ivoa-onto/src/main/resources/IVOAO.owl>
4. Select Messier object ID, right ascension, and declination from all entries:
   select ID, RA, Dec from {C} ivoao:identification {ID}; ast:RightAscension {RA}; ast:Declination {Dec} using namespace ivoao = <http://archive.astro.umd.edu/ivoa-onto/src/main/resources/IVOAO.owl>, ast = <http://archive.astro.umd.edu/ivoa-onto/src/main/resources/astronomy.owl>
5. Select the Messier object ID and spectral classification of all globular clusters:
   select ID, spectralClass, GlC^? from {C} ivoao:identification {ID};ast:SpectralClassification {spectralClass}; ast:globularCluster {GlC} using namespace ivoao = <http://archive.astro.umd.edu/ivoa-onto/src/main/resources/IVOAO.owl>, ast = <http://archive.astro.umd.edu/ivoa-onto/src/main/resources/astronomy.owl>
6. Select entry URIs plus ID and spectral classification for all globular clusters:
   select globularCluster, ID, spectralClass from {globularCluster} ast:globularCluster {}; [ivoao:identification {ID}]; [ast:SpectralClassification {spectralClass}] USING NAMESPACE ast = <http://archive.astro.umd.edu/ivoa-onto/src/main/resources/astronomy.owl>, ivoao = <http://archive.astro.umd.edu/ivoa-onto/src/main/resources/IVOAO.owl>
7. Select object entry, ID, RA, Dec for all entries:
   select object, ID, RA, Dec from {object} ivoao:identification {ID}; ast:RightAscension {RA}; ast:Declination {Dec} using namespace ast = <http://www.ivoa.net/ontology/astronomy.owl#>, ivoao = <http://www.ivoa.net/ontology/IVOAO.owl#>, phys = <http://www.ivoa.net/ontology/physics.owl#>
8. Select object entry, ID, spectral classification, and object type where ID equals "M 61":
   select object, ID, SpecClass, objectType from {object} ivoao:identification {ID}; ast:SpectralClassification {SpecClass}; serql:directType {objectType} where ID = "M 61" using namespace ast = <http://www.ivoa.net/ontology/astronomy.owl#>, ivoao = <http://www.ivoa.net/ontology/IVOAO.owl#>, phys = <http://www.ivoa.net/ontology/physics.owl#>
9. Select object entry, ID, spectral classification, and object type for any object with an "F" type spectral classification:
   select object, ID, SpecClass, objectType from {object} ivoao:identification {ID}; ast:SpectralClassification {SpecClass}; serql:directType {objectType} where SpecClass like "F*" using namespace ast = <http://www.ivoa.net/ontology/astronomy.owl#>, ivoao = <http://www.ivoa.net/ontology/IVOAO.owl#>, phys = <http://www.ivoa.net/ontology/physics.owl#>

More interesting data queries

1. Select all entries that are subclasses of ast:starCluster:
   select distinct * from {C} rdf:type {} rdfs:subClassOf {ast:starCluster} using namespace ast = <http://www.ivoa.net/ontology/astronomy.owl#>
2. Select ID, RA, Dec, flux, and spectral class of all entries that are subclasses of ast:starCluster:
   select ID, RA, Dec, Flux, SpecClass from {C} rdf:type {} rdfs:subClassOf {ast:starCluster}; ivoao:identification {ID}; ast:RightAscension {RA}; ast:Declination {Dec}; phys:flux {Flux}; ast:SpectralClassification {SpecClass} using namespace ast = <http://www.ivoa.net/ontology/astronomy.owl#>, ivoao = <http://www.ivoa.net/ontology/IVOAO.owl#>, phys = <http://www.ivoa.net/ontology/physics.owl#>
3. Box query: select all objects plus their ID, RA, Dec, and object type that fall into a box defined by 180.0 < RA < 190.0 and +11.0< Dec < +14.0 :
   select object, ID, RA, Dec, objectType from {object} ivoao:identification {ID}; ast:RightAscension {RA}; ast:Declination {Dec}; serql:directType {objectType} where RA > "180.0"^^xsd:float and Dec < "14.0"^^xsd:float and RA < "190.0"^^xsd:float and Dec > "11.0"^^xsd:float using namespace ast = <http://www.ivoa.net/ontology/astronomy.owl#>, ivoao = <http://www.ivoa.net/ontology/IVOAO.owl#>, phys = <http://www.ivoa.net/ontology/physics.owl#>
4. More specific box query: select all galaxies (and subclasses of galaxies) plus their ID, RA, Dec, and object type that fall into a box defined by 180.0 < RA < 190.0 and +11.0< Dec < +14.0
   select object, ID, RA, Dec, objectType from {object} ivoao:identification {ID}; ast:RightAscension {RA}; ast:Declination {Dec}; serql:directType {objectType} rdfs:subClassOf {ast:galaxy} where RA > "180.0"^^xsd:float and Dec < "14.0"^^xsd:float and RA < "190.0"^^xsd:float and Dec > "11.0"^^xsd:float using namespace ast = <http://www.ivoa.net/ontology/astronomy.owl#>, ivoao = <http://www.ivoa.net/ontology/IVOAO.owl#>, phys = <http://www.ivoa.net/ontology/physics.owl#>
5. Put it all together: select all types of star cluster (including globular clusters and open star clusters) with "F" or "A" type spectral classifications that fall into a box defined by 244.0 < RA < 276.0 and -30.0 < Dec < -10.0 (warning: the "OR" query takes a while to process):
   select object, ID, RA, Dec, SpecClass, objectType from {object} ivoao:identification {ID}; ast:RightAscension {RA}; ast:Declination {Dec}; ast:SpectralClassification {SpecClass}; serql:directType {objectType} rdfs:subClassOf {ast:starCluster} where SpecClass like "A" or SpecClass like "F*" and Dec < "-10.0"^^xsd:float and RA < "276.0"^^xsd:float and Dec > "-30.0"^^xsd:float and RA > "244.0"^^xsd:float using namespace ast = <http://www.ivoa.net/ontology/astronomy.owl#>, ivoao = <http://www.ivoa.net/ontology/IVOAO.owl#>, phys = <http://www.ivoa.net/ontology/physics.owl#>

serql:directSubClassOf {ast:galaxy} using namespace ast = <http://archive.astro.umd.edu/ivoa-onto/src/main/resources/astronomy.owl>

select SUB from {SUB} rdfs:subClassOf {ast:galaxy} using namespace ast = <http://archive.astro.umd.edu/ivoa-onto/src/main/resources/astronomy.owl>

select C from {C} rdfs:subClassOf {ast:starCluster} using namespace ast = <http://archive.astro.umd.edu/ivoa-onto/src/main/resources/astronomy.owl>

1. Select all direct subclasses of "galaxy":SELECT * FROM {directSub} serql:directSubClassOf {directSuper} rdfs:subClassOf {<http://www.ivoa.net/ontology/astronomy.owl#galaxy>}
2. Select all subclasses of "galaxy". Compare this with results from the above query; a class is considered a subclass of itself, but not a direct subclass of itself:SELECT * FROM {directSub} rdfs:subClassOf {directSuper} rdfs:subClassOf {<http://www.ivoa.net/ontology/astronomy.owl#galaxy>}

Well-formatted but empty subclass query: select SUB, ID, spectralClass from {SUB} rdfs:subClassOf {ast:starCluster}; [ivoao:identification {ID}]; [ast:SpectralClassification {spectralClass}] USING NAMESPACE ast = <http://archive.astro.umd.edu/ivoa-onto/src/main/resources/astronomy.owl>, ivoao = <http://archive.astro.umd.edu/ivoa-onto/src/main/resources/IVOAO.owl>

Ditto: select clusters from {clusters} rdfs:subClassOf {ast:starCluster} USING NAMESPACE ast = <http://archive.astro.umd.edu/ivoa-onto/src/main/resources/astronomy.owl>

Well-formatted, but returns class names instead of entries: select clusters from {clusters} rdfs:subClassOf {<http://www.ivoa.net/ontology/astronomy.owl#starCluster>} USING NAMESPACE ast = <http://archive.astro.umd.edu/ivoa-onto/src/main/resources/astronomy.owl>

Well-formatted, but empty: select ID from {} rdfs:subClassOf {<http://www.ivoa.net/ontology/astronomy.owl#starCluster>} ivoao:identification {ID} USING NAMESPACE ast = <http://archive.astro.umd.edu/ivoa-onto/src/main/resources/astronomy.owl>, ivoao = <http://archive.astro.umd.edu/ivoa-onto/src/main/resources/IVOAO.owl>

Returns subclasses of starCluster: select C from {C} rdf:type {rdfs:Class}; rdfs:subClassOf {<http://www.ivoa.net/ontology/astronomy.owl#starCluster>} USING NAMESPACE ast = <http://archive.astro.umd.edu/ivoa-onto/src/main/resources/astronomy.owl>

Select all classes to which M62.rdf belongs (returns only "Resource", so try using that):#SELECT X FROM {<http://msslxx.mssl.ucl.ac.uk:8080/sesame/m62.rdf>} rdf:type {X} USING NAMESPACE ast = <http://archive.astro.umd.edu/ivoa-onto/src/main/resources/astronomy.owl>

Select all rdf:Resources (returns all classes and all entries for Messier objects): SELECT Resource FROM {Resource} rdf:type {<http://www.w3.org/2000/01/rdf-schema#Resource>} USING NAMESPACE ast = <http://archive.astro.umd.edu/ivoa-onto/src/main/resources/astronomy.owl>

As above, but returns only classes that are subclasses of starCluster. Want instances of starCluster subclasses (select all resources that are also subclasses of starCluster).

FROM {Resource} rdf:type {<http://www.w3.org/2000/01/rdf-schema#Resource>}; rdfs:subClassOf {<http://www.ivoa.net/ontology/astronomy.owl#starCluster>} USING NAMESPACE ast = <http://archive.astro.umd.edu/ivoa-onto/src/main/resources/astronomy.owl>

Select all entries containing Right Ascension: SELECT DISTINCT * FROM {C} ast:RightAscension {} USING NAMESPACE ast = <http://archive.astro.umd.edu/ivoa-onto/src/main/resources/astronomy.owl

Empty (also with rdf:predicate, rdf:subject): SELECT DISTINCT * FROM {C} rdf:object {} USING NAMESPACE ast = <http://archive.astro.umd.edu/ivoa-onto/src/main/resources/astronomy.owl>

NOTE: need to regenerate RDF data. Set rdf:type to a celestial object type, ensure that ast namespace points to http://www.ivoa.net/ontology/astronomy.owl#, don't forget "#" after namespaces. New subclass queries:

1. Select entries which are subclasses of galaxy:
   select distinct * from {C}

1. Select entries which are direct subclasses of galaxy (i.e., does not include galaxy itself):
   select distinct * from {C} rdf:type {} serql:directSubClassOf {ast:galaxy} using namespace ast = <http://www.ivoa.net/ontology/astronomy.owl#>
2. Select names of subclasses of galaxy:
   SELECT * FROM {sub} rdfs:subClassOf {<http://www.ivoa.net/ontology/astronomy.owl#galaxy>}
3. Select names of direct subclasses of galaxy:
   SELECT * FROM {sub} serql:directSubClassOf {<http://www.ivoa.net/ontology/astronomy.owl#galaxy>}
4. Select all properties and their values for M10:
   select * from {<http://msslxx.mssl.ucl.ac.uk:8080/sesame/#m10>} p {Y} using namespace ast = <http://www.ivoa.net/ontology/astronomy.owl#>
5. Select ID, RA, Dec, flux, spectral classification from all subclasses of starCluster:
   select ID, RA, Dec, Flux, SpecClass^? from {C} rdf:type {} rdfs:subClassOf {ast:starCluster}; ivoao:identification {ID}; ast:RightAscension {RA}; ast:Declination {Dec}; phys:flux {Flux}; ast:SpectralClassification {SpecClass} using namespace ast = <http://www.ivoa.net/ontology/astronomy.owl#>, ivoao = <http://www.ivoa.net/ontology/IVOAO.owl#>, phys = <http://www.ivoa.net/ontology/physics.owl#>

select distinct * from {C} rdf:type {} rdfs:subClassOf {ast:galaxy}; ast:RightAscension {RA}; ast:Declination {Dec} where RA > "10.0"^^xsd:float and Dec < "41.0"^^xsd:float and RA < "11.0"^^xsd:float and Dec > "42.0"^^xsd:float using namespace ast = <http://www.ivoa.net/ontology/astronomy.owl#>

-- ElizabethAuden - 11 Feb 2008