Unable to generate OBDA from R2RML using CLI

[UtkrshS]

I am not able to generate the OBDA file using the R2RML file. It gives me an error mentioned below.

Command used: ./ontop mapping to-obda -i input-r2rml.ttl -o output.obda

Can someone pls help?

Error received:

it.unibz.inf.ontop.exception.InvalidOntopConfigurationException: Impossible to get the JDBC driver. Reason: No suitable driver
at it.unibz.inf.ontop.injection.impl.OntopSQLCoreSettingsImpl.lambda$extractJdbcDriver$11(OntopSQLCoreSettingsImpl.java:121)
at java.base/java.util.Optional.orElseGet(Optional.java:364)
at it.unibz.inf.ontop.injection.impl.OntopSQLCoreSettingsImpl.extractJdbcDriver(OntopSQLCoreSettingsImpl.java:115)
at it.unibz.inf.ontop.injection.impl.OntopSystemSQLSettingsImpl.loadProperties(OntopSystemSQLSettingsImpl.java:31)
at it.unibz.inf.ontop.injection.impl.OntopSystemSQLSettingsImpl.(OntopSystemSQLSettingsImpl.java:22)
at it.unibz.inf.ontop.injection.impl.OntopStandaloneSQLSettingsImpl.loadProperties(OntopStandaloneSQLSettingsImpl.java:21)
at it.unibz.inf.ontop.injection.impl.OntopStandaloneSQLSettingsImpl.(OntopStandaloneSQLSettingsImpl.java:16)
at it.unibz.inf.ontop.injection.impl.OntopSQLOWLAPIConfigurationImpl$BuilderImpl.build(OntopSQLOWLAPIConfigurationImpl.java:155)
at it.unibz.inf.ontop.cli.OntopR2RMLToOBDA.run(OntopR2RMLToOBDA.java:39)
at it.unibz.inf.ontop.cli.Ontop.main(Ontop.java:18)
Exception in thread "main" java.lang.AssertionError
at it.unibz.inf.ontop.cli.Ontop.main(Ontop.java:30)

[LorenzBuehmann]

According to the docs, the converter

1. does consider DB metadata, so it either
   a) tries to extract metadata from the DB, or
   b) it expects a given DB metadata file (see docs)
2. or the above requirements can be ignored with --force argument

In case of 1a (which is the default case), Ontop has to open a JDBC connection. That means Ontop needs the corresponding JDBC driver in the classpath. The JDBC drivers of all the supported DBs aren't shipped with the Ontop distribution (due to licenses I guess),thus, you have to download the one for your DB system and put it into the jdbc folder of your Ontop distribution.

Long story short, either download the JDBC driver or simply bypass this with --force