How to construct query to change all the values of properties in a triple to strings? Suppose for given graph all values of properties are a mixture of strings and decimals. SELECT DISTINCT ?sa ?oa FROM <http://ucb.com/nbeabase> WHERE { ?sa a <http://ucb.com/nbeabase/resource/Batch> . ?sa <http://ucb.com/nbeabase/resource/chemAbsNo> ?oa . FILTER regex(?oa, '-','i') } In order to change the values to string, should be executed the following statement: SQL> SPARQL INSERT INTO GRAPH <http://ucb.com/nbeabase> { ?sa <http://ucb.com/nbeabase/resource/sampleId> `str (?oa)` } WHERE { ?sa <http://ucb.com/nbeabase/resource/chemAbsNo> ?oa . FILTER regex(?oa, '-','i') } Related Virtuoso Tips and Tricks Collection RDF Data Access and Data Management