Jakub Galgonek

Some SPARQL queries are not evaluated correctly if the xsd:string datatype is present

5

I use Linked Data Views and I observed that some SPARQL queries are not evaluated correctly if they contain string literals with the xsd:string datatype. Without this datatype (i.e., if...

datatype of a literal with a language tag

9

Hi, the function _datatype_ should return rdf:langString, if the literal has a language tag. However, the following query does not return the expected result: ``` sparql select ?literal datatype(?literal) as...

Options datatype and language are ignored by Literal classes

7

It seems that Virtuoso ignores `datatype` and `language` options in `create Literal class` statements. If I create the table — ``` create table "TEST"."TEST"."EXAMPLE"( id integer primary key, name VARCHAR(100)...

Variable in T_IN list and corresponding variable in T_OUT get values from columns that are too different

1

While working on a study comparing different approaches to query the neXtProt dataset, I have observed that Virtuoso returns wrong results in some cases. If I create the tables —...

Internal error: ssg_print_box_as_sql_atom (): bad mode

1

While working on a study comparing different approaches to query the neXtProt dataset, I have observed that Virtuoso returns wrong results in some cases. If I create the table —...

Incorrect "TOP 1" optimization

1

While working on a study comparing different approaches to query the neXtProt dataset, I have observed that Virtuoso returns wrong results in some cases. If I create the tables —...

Missing IS NOT NULL condition

1

While working on a study comparing different approaches to query the neXtProt dataset, I have observed that Virtuoso returns wrong results in some cases. If I create the tables —...

Wrong behaviour of SPARQL DISTINCT

1

While working on a study comparing different approaches to query the neXtProt dataset, I have observed that Virtuoso returns wrong results in some cases. If I create the table —...

### Description In PostgreSQL, the substr function supports only integer parameters to specify the start position and the length. However, in some cases, Ontop generates SQL queries that use values...

Incorrect translations of object lists combined with property paths

3

### Description In Ontop, combinations of object lists and property paths are interpreted incorrectly. For example, Ontop interprets pattern `?I ex:prop1 / ex:prop2 ?V1,?V2` as: ``` ?I ex:prop1 _:bn. _:bn...