predicateMap's issue in R2RML

Support
1

Hi. I have started testing stardog’s r2rml capabilities and they look good. However, I have noticed that predicateMap have an issue. I have a predicate mapping as follows:

rr:predicateMap [ rr:template "http://www.ontology.com/ontologies/property/{PROPERTY}"] ; # PROPERTY is a column name that is never null

I get this error:

ColumnOrConst is null.
The detailed stack trace for the error is:
com.complexible.stardog.cli.CliException: ColumnOrConst is null.
        at com.complexible.stardog.cli.impl.ConnectionCommand.call(ConnectionCommand.java:73)
        at com.complexible.stardog.cli.CLIBase.execute(CLIBase.java:55)
        at com.complexible.stardog.cli.admin.CLI.main(CLI.java:182)
Caused by: com.complexible.stardog.StardogException: ColumnOrConst is null.
        at com.complexible.stardog.protocols.http.client.BaseHttpClient.checkResponseCode(BaseHttpClient.java:492)
        at com.complexible.stardog.protocols.http.client.BaseHttpClient.execute(BaseHttpClient.java:324)
        at com.complexible.stardog.protocols.http.client.BaseHttpClient.executeHttpPost(BaseHttpClient.java:662)
        at com.complexible.stardog.protocols.http.client.BaseHttpClient.executeHttpPost(BaseHttpClient.java:637)
        at com.complexible.stardog.protocols.http.client.HttpVirtualGraphAdminClientImpl.addOrUpdate(HttpVirtualGraphAdminClientImpl.java:233)
        at com.complexible.stardog.protocols.http.client.HttpVirtualGraphAdminClientImpl.addGraph(HttpVirtualGraphAdminClientImpl.java:202)
        at com.complexible.stardog.protocols.http.client.HttpVirtualGraphAdminClientImpl.addGraph(HttpVirtualGraphAdminClientImpl.java:51)
        at com.complexible.stardog.protocols.http.client.AbstractVirtualGraphAdminConnection.addGraph(AbstractVirtualGraphAdminConnection.java:86)
        at com.complexible.stardog.virtual.cli.VirtualGraphImport.execute(VirtualGraphImport.java:135)
        at com.complexible.stardog.cli.impl.ConnectionCommand.call(ConnectionCommand.java:61)

Any help or suggestions? I tried quoting the column name as well. Rest of the mappings work fine. This column (PROPERTY) is never null in the DB.

additionally, If I use property instead of PROPERTY, I get the error that column does not exist.

Thanks

2

Borna,

You are using Stardog 5.0 (not 5.0.1), correct? Can you share the exception from the log file when running this command?

Jess

3

yes I am. Please see below. Do you think using 5.0.1 will resolve the issue?

ERROR 2017-07-11 14:09:52,007 [XNIO-1 task-96] com.stardog.http.server.undertow.ErrorHandling:writeError(179): Unexpected error on the server
java.lang.NullPointerException: ColumnOrConst is null.
        at eu.optique.api.mapping.impl.TermMapImpl.<init>(TermMapImpl.java:89) ~[stardog-virtual-api-5.0.jar:?]
        at eu.optique.api.mapping.impl.ObjectMapImpl.<init>(ObjectMapImpl.java:46) ~[stardog-virtual-api-5.0.jar:?]
        at eu.optique.api.mapping.impl.MappingFactoryImpl.createObjectMap(MappingFactoryImpl.java:131) ~[stardog-virtual-api-5.0.jar:?]
        at com.complexible.stardog.virtual.R2RMLUtils.newConstantTermMap(R2RMLUtils.java:234) ~[stardog-virtual-core-5.0.jar:?]
        at com.complexible.stardog.virtual.vega.MappedPredicateIndex$MatchedPredicate.<init>(MappedPredicateIndex.java:126) ~[stardog-virtual-core-5.0.jar:?]
        at com.complexible.stardog.virtual.vega.MappedPredicateIndex$MatchedPredicate.<init>(MappedPredicateIndex.java:119) ~[stardog-virtual-core-5.0.jar:?]
        at com.complexible.stardog.virtual.vega.MappedPredicateIndex.lambda$buildObjectMapIndex$8(MappedPredicateIndex.java:66) ~[stardog-virtual-core-5.0.jar:?]
        at java.util.ArrayList.forEach(ArrayList.java:1249) ~[?:1.8.0_131]
        at java.util.Collections$UnmodifiableCollection.forEach(Collections.java:1080) ~[?:1.8.0_131]
        at com.complexible.stardog.virtual.vega.MappedPredicateIndex.buildObjectMapIndex(MappedPredicateIndex.java:66) ~[stardog-virtual-core-5.0.jar:?]
        at com.complexible.stardog.virtual.vega.MappedPredicateIndex.<init>(MappedPredicateIndex.java:45) ~[stardog-virtual-core-5.0.jar:?]
        at com.complexible.stardog.virtual.vega.VegaVirtualGraph.<init>(VegaVirtualGraph.java:166) ~[stardog-virtual-core-5.0.jar:?]
        at com.complexible.stardog.virtual.DefaultVirtualGraphRegistry._add(DefaultVirtualGraphRegistry.java:197) ~[stardog-virtual-core-5.0.jar:?]
        at com.complexible.stardog.virtual.DefaultVirtualGraphRegistry.add(DefaultVirtualGraphRegistry.java:117) ~[stardog-virtual-core-5.0.jar:?]
        at com.complexible.stardog.protocols.http.server.virtual.admin.VirtualGraphHttpService.addVG(VirtualGraphHttpService.java:257) ~[stardog-virtual-protocols-http-server-5.0.jar:?]
        at com.complexible.stardog.protocols.http.server.virtual.admin.VirtualGraphHttpService.add(VirtualGraphHttpService.java:105) ~[stardog-virtual-protocols-http-server-5.0.jar:?]
        at com.stardog.http.server.undertow.jaxrs.ExtractRoutes.lambda$handleIt$91(ExtractRoutes.java:186) ~[stardog-protocols-http-server-5.0.jar:?]
        at org.apache.shiro.subject.support.SubjectRunnable.doRun(SubjectRunnable.java:120) ~[shiro-core-1.2.3.jar:1.2.3]
        at org.apache.shiro.subject.support.SubjectRunnable.run(SubjectRunnable.java:108) ~[shiro-core-1.2.3.jar:1.2.3]
        at com.stardog.http.server.undertow.ErrorHandling.lambda$safeDispatch$46(ErrorHandling.java:70) ~[stardog-protocols-http-server-5.0.jar:?]
        at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142) [?:1.8.0_131]
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617) [?:1.8.0_131]
        at java.lang.Thread.run(Thread.java:748) [?:1.8.0_131]
4

Switching to 5.0.1 did not help :frowning:

5

Are you able to share your mappings, either here or in private?

6

In my experience, all the predicateMaps produce the same error. Here is my map:

<#abc>
                a rr:TriplesMap;
                rr:logicalTable [rr:tableName "product"];
                rr:subjectMap [
                                rr:template "http://www.abc.com/ontologies/prod/{\"PROD_ID\"}";
                                rr:class ex:Product;
                ];
                rr:predicateObjectMap [
                    rr:predicateMap [rr:template "http://www.abc.com/ontologies/prop/{\"PROPERTY_NAME\"}"; ]
                    rr:objectMap    [ rr:column "\"PROPERTY_VALUE\""; rr:datatype xsd:string]
                ].
7

Template (and column) predicate maps will be supported in the next release.

8

This topic was automatically closed 14 days after the last reply. New replies are no longer allowed.