# (rdf4j-stardog) StardogRepositoryConnection::hasStatement always returns true when passing BNodes **URL:** \ **Category:** Support\ **Created:** [September 17, 2018, 7:41am UTC](https://community.stardog.com/t/rdf4j-stardog-stardogrepositoryconnection-hasstatement-always-returns-true-when-passing-bnodes/1296 "2018-09-17T07:41:56Z")\ **Posts on this page:** 9\ **Page:** 1
**Author:** ![MiguelAraCo](https://yyz2.discourse-cdn.com/flex030/user_avatar/community.stardog.com/miguelaraco/32/306_2.png) [@MiguelAraCo](https://community.stardog.com/u/MiguelAraCo)\ **Post date:** [September 17, 2018, 7:41am UTC](https://community.stardog.com/t/rdf4j-stardog-stardogrepositoryconnection-hasstatement-always-returns-true-when-passing-bnodes/1296/1 "2018-09-17T07:41:56Z")
The following code will always return `true` regardless of the existence of statements with that subject: ```auto BNode subject = SimpleValueFactory.getInstance().createBNode( "some-id" ); connection.hasStatement( subject, null, null, false ); ``` In the past this code used to work since the implementation of `hasStatement` was the one that `AbstractRepositoryConnection` has, but recently this was changed to use a SPARQL query instead. Since SPARQL queries can't reference BNodes directly, the subject gets replaced by a SPARQL variable and returns true always. ## Workaround To make it work, we changed the implementation of the method to: ```auto public boolean hasStatement( Resource subj, IRI pred, Value obj, boolean includeInferred, Resource... contexts ) throws RepositoryException { StringBuilder triplePattern = new StringBuilder( "{ " ); StringBuilder auxiliaryPatterns = new StringBuilder(); // Subject if ( subj == null ) { triplePattern.append( " ?s" ); } else if ( subj instanceof BNode ) { triplePattern.append( " ?s" ); auxiliaryPatterns.append( " FILTER( STR( ?s ) = \"" ).append( ( (BNode) subj ).getID() ).append( "\" ) ." ); } else { triplePattern.append( " " ).append( SesameQueryUtils.getSPARQLQueryString( APIMapping.toSesameValue( subj ) ) ); } // Predicate if ( pred == null ) { triplePattern.append( " ?p" ); } else { triplePattern.append( " " ).append( SesameQueryUtils.getSPARQLQueryString( APIMapping.toSesameValue( pred ) ) ); } // Object if ( obj == null ) { triplePattern.append( " ?o" ); } else if ( obj instanceof BNode ) { triplePattern.append( " ?o" ); auxiliaryPatterns.append( " FILTER( STR( ?o ) = \"" ).append( ( (BNode) obj ).getID() ).append( "\" ) ." ); } else { triplePattern.append( " " ).append( SesameQueryUtils.getSPARQLQueryString( APIMapping.toSesameValue( obj ) ) ); } triplePattern.append( " ." ) .append( auxiliaryPatterns ) .append( " }" ); if ( contexts.length > 0 ) { for ( Resource context : contexts ) { String query = String.format( "ASK { GRAPH <%s> %s }", context.stringValue(), triplePattern ); if ( this.mConnection.ask( query ).reasoning( includeInferred ).execute() ) return true; } return false; } else { String query = String.format( "ASK %s", triplePattern ); return this.mConnection.ask( query ).reasoning( includeInferred ).execute(); } } ``` ## Environment - Stardog: 5.3.4 - rdf4j-stardog: 5.3.4 ---
**Author:** ![stephen](https://yyz2.discourse-cdn.com/flex030/user_avatar/community.stardog.com/stephen/32/27_2.png) [@stephen](https://community.stardog.com/u/stephen)\ **Post date:** [October 2, 2018, 4:33pm UTC](https://community.stardog.com/t/rdf4j-stardog-stardogrepositoryconnection-hasstatement-always-returns-true-when-passing-bnodes/1296/3 "2018-10-02T16:33:52Z")
Hi Miguel, Thank you very much for the detailed bug reports both here and in your [other topic](https://community.stardog.com/t/rdf4j-stardog-stardogrepositoryconnection-getstatements-wont-return-the-correct-statements-when-passing-bnodes/1297). We have tracked down the underlying cause for these issues and the fix for them will be included in the 5.3.5 release. ---
**Author:** ![stephen](https://yyz2.discourse-cdn.com/flex030/user_avatar/community.stardog.com/stephen/32/27_2.png) [@stephen](https://community.stardog.com/u/stephen)\ **Post date:** [October 2, 2018, 4:34pm UTC](https://community.stardog.com/t/rdf4j-stardog-stardogrepositoryconnection-hasstatement-always-returns-true-when-passing-bnodes/1296/4 "2018-10-02T16:34:35Z")
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**Author:** ![mhernandeza](https://avatars.discourse-cdn.com/v4/letter/m/a3d4f5/32.png) [@mhernandeza](https://community.stardog.com/u/mhernandeza)\ **Post date:** [September 11, 2019, 10:40pm UTC](https://community.stardog.com/t/rdf4j-stardog-stardogrepositoryconnection-hasstatement-always-returns-true-when-passing-bnodes/1296/5 "2019-09-11T22:40:58Z")
Hi Stephen, I was just reviewing this solution and was wondering if you would recommend the filtering process first stated `FILTER ( STR( ?s ) = "b0" )` or if an alternative like the following would be a more appropriate solution: `FILTER( ?s = bnode( "b0" ) )`. Also, I am using this code along with Stardog's 7.0.1 release and I was wondering if there was a particular reason as to why this issue wasn't resolved. This is also related to the [other topic](https://community.stardog.com/t/rdf4j-stardog-stardogrepositoryconnection-getstatements-wont-return-the-correct-statements-when-passing-bnodes/1297) you mentioned in your comment. Thanks for your continuous support! ---
**Author:** ![system](https://canada1.discourse-cdn.com/flex030/uploads/stardog/original/2X/e/ed66b48a616f505106a4acde3c9cee7e6da9bc67.svg) [@system](https://community.stardog.com/u/system)\ **Post date:** [April 1, 2022, 1:33am UTC](https://community.stardog.com/t/rdf4j-stardog-stardogrepositoryconnection-hasstatement-always-returns-true-when-passing-bnodes/1296/6 "2022-04-01T01:33:55Z")
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**Author:** ![system](https://canada1.discourse-cdn.com/flex030/uploads/stardog/original/2X/e/ed66b48a616f505106a4acde3c9cee7e6da9bc67.svg) [@system](https://community.stardog.com/u/system)\ **Post date:** [April 7, 2022, 8:28pm UTC](https://community.stardog.com/t/rdf4j-stardog-stardogrepositoryconnection-hasstatement-always-returns-true-when-passing-bnodes/1296/7 "2022-04-07T20:28:43Z")
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**Author:** ![system](https://canada1.discourse-cdn.com/flex030/uploads/stardog/original/2X/e/ed66b48a616f505106a4acde3c9cee7e6da9bc67.svg) [@system](https://community.stardog.com/u/system)\ **Post date:** [April 14, 2022, 10:56pm UTC](https://community.stardog.com/t/rdf4j-stardog-stardogrepositoryconnection-hasstatement-always-returns-true-when-passing-bnodes/1296/8 "2022-04-14T22:56:55Z")
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**Author:** ![system](https://canada1.discourse-cdn.com/flex030/uploads/stardog/original/2X/e/ed66b48a616f505106a4acde3c9cee7e6da9bc67.svg) [@system](https://community.stardog.com/u/system)\ **Post date:** [April 23, 2022, 10:51am UTC](https://community.stardog.com/t/rdf4j-stardog-stardogrepositoryconnection-hasstatement-always-returns-true-when-passing-bnodes/1296/9 "2022-04-23T10:51:41Z")
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**Author:** ![system](https://canada1.discourse-cdn.com/flex030/uploads/stardog/original/2X/e/ed66b48a616f505106a4acde3c9cee7e6da9bc67.svg) [@system](https://community.stardog.com/u/system)\ **Post date:** [May 2, 2022, 6:47am UTC](https://community.stardog.com/t/rdf4j-stardog-stardogrepositoryconnection-hasstatement-always-returns-true-when-passing-bnodes/1296/10 "2022-05-02T06:47:16Z")