Export from to CSV (source: https://www.mail-archive.com/virtuoso-users@lists.sourceforge.net/msg06346.html)

csvExport.sql

create procedure
cbw.DBA.csvExport( IN in_query VARCHAR, IN filename VARCHAR )
{

        declare query varchar;
        query := split_and_decode(in_query,0,'%');
        
        file_delete(filename,1);

        declare meta, _dt any;
        declare errorCode, errorMessage varchar;
        declare inx integer;
        exec (query, errorCode, errorMessage, vector(), 0, meta, _dt);

        declare linestr varchar;
        declare flag integer;
        linestr := '';
        if (meta <> 0) {
                flag := 0;
                FOREACH (varchar col in meta[0]) DO {
                        if (flag = 0) flag := 1;
                        else linestr:=concat(linestr,',');
                        linestr := concat(linestr,'"',col[0],'"');
                }
                string_to_file(filename,linestr,-2);
                string_to_file(filename,'\n',-1);
                -- Header is now complete
                inx := 0;
                if (_dt <> 0) {
                  while (inx < length (_dt))
                    {
                                linestr := '';
                                flag := 0;
                                FOREACH (any col in _dt[inx]) DO {
                                        if (flag = 0) flag := 1;
                                        else linestr:=concat(linestr,',');
                                        linestr := concat(linestr,'"',col,'"');
                                }
                                string_to_file(filename,linestr,-1);
                                string_to_file(filename,'\n',-1);
                        inx := inx + 1;
                                
                    }
                }
        } else return 'No records or some error';

}