public void setUp() throws Exception {
    pm = new SimplePrefixManager();
    OBDADataFactory pfac = OBDADataFactoryImpl.getInstance();
    OBDADataFactory tfac = OBDADataFactoryImpl.getInstance();
    query = tfac.getDatalogProgram();

    LinkedList<Term> innerterms = new LinkedList<Term>();
    innerterms.add(tfac.getVariable("id"));

    //		IRIFactory fact = new IRIFactory();

    List<Term> terms = new LinkedList<Term>();
    terms.add(
        tfac.getFunction(
            pfac.getPredicate("http://obda.org/onto.owl#person-individual", 1), innerterms));

    Function body =
        tfac.getFunction(pfac.getClassPredicate("http://obda.org/onto.owl#Person"), terms);

    terms = new LinkedList<Term>();
    terms.add(tfac.getVariable("id"));
    Function head = tfac.getFunction(pfac.getPredicate("http://obda.org/predicates#q", 1), terms);

    rule1 = tfac.getCQIE(head, Collections.singletonList(body));
    query.appendRule(rule1);
  }
Beispiel #2
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  /** Returns a new term with the updated references. */
  private Term updateTerm(Term term, LookupTable lookupTable) {
    Term result = null;

    if (term instanceof Variable) {
      Variable var = (Variable) term;
      String varName = var.getName();
      String termName = lookupTable.lookup(varName);
      if (termName == null) {
        final String msg =
            String.format(
                "Error in identifying column name \"%s\", please check the query source in the mappings.\nPossible reasons:\n1. The name is ambiguous, or\n2. The name is not defined in the database schema.",
                var);
        throw new RuntimeException(msg);
      }
      result = dfac.getVariable(termName);

    } else if (term instanceof Function) {
      Function func = (Function) term;
      List<Term> terms = func.getTerms();
      List<Term> newterms = new LinkedList<Term>();
      for (Term innerTerm : terms) {
        newterms.add(updateTerm(innerTerm, lookupTable));
      }
      result = dfac.getFunction(func.getFunctionSymbol(), newterms);
    } else if (term instanceof Constant) {
      result = term.clone();
    }
    return result;
  }
Beispiel #3
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  public DatalogProgram constructDatalogProgram() {
    DatalogProgram datalog = dfac.getDatalogProgram();
    LinkedList<String> errorMessage = new LinkedList<String>();
    for (OBDAMappingAxiom axiom : mappingList) {
      try {
        // Obtain the target and source query from each mapping axiom in
        // the model.
        CQIE targetQuery = (CQIE) axiom.getTargetQuery();

        // Get the parsed sql, since it is already parsed by the mapping
        // parser
        // consider also MetaMappingExpander
        // VisitedQuery queryParsed = ...;

        OBDASQLQuery sourceQuery = (OBDASQLQuery) axiom.getSourceQuery();

        // Construct the SQL query tree from the source query
        VisitedQuery queryParsed = translator.constructParser(sourceQuery.toString());

        // Create a lookup table for variable swapping
        LookupTable lookupTable = createLookupTable(queryParsed);

        // We can get easily the table from the SQL
        ArrayList<RelationJSQL> tableList = queryParsed.getTableSet();

        // Construct the body from the source query
        ArrayList<Function> atoms = new ArrayList<Function>();
        for (RelationJSQL table : tableList) {
          // Construct the URI from the table name
          String tableName = table.getGivenName();
          String predicateName = tableName;

          // Construct the predicate using the table name
          int arity = dbMetaData.getDefinition(tableName).countAttribute();
          Predicate predicate = dfac.getPredicate(predicateName, arity);

          // Swap the column name with a new variable from the lookup
          // table
          List<Term> terms = new ArrayList<Term>();
          for (int i = 1; i <= arity; i++) {
            String columnName =
                dbMetaData.getFullQualifiedAttributeName(tableName, table.getAlias(), i);
            String termName = lookupTable.lookup(columnName);
            if (termName == null) {
              throw new RuntimeException(
                  "Column '" + columnName + "'was not found in the lookup table: ");
            }
            Term term = dfac.getVariable(termName);
            terms.add(term);
          }
          // Create an atom for a particular table
          Function atom = dfac.getFunction(predicate, terms);
          atoms.add(atom);
        }

        // For the join conditions WE STILL NEED TO CONSIDER NOT EQUI
        // JOIN
        ArrayList<Expression> joinConditions = queryParsed.getJoinCondition();
        for (Expression predicate : joinConditions) {

          Function atom = getFunction(predicate, lookupTable);
          atoms.add(atom);
        }

        // For the selection "where" clause conditions
        SelectionJSQL selection = queryParsed.getSelection();
        if (selection != null) {

          // Stack for filter function
          Stack<Function> filterFunctionStack = new Stack<Function>();

          Expression conditions = selection.getRawConditions();
          Function filterFunction = getFunction(conditions, lookupTable);
          filterFunctionStack.push(filterFunction);

          // The filter function stack must have 1 element left
          if (filterFunctionStack.size() == 1) {
            Function filterFunct = filterFunctionStack.pop();
            Function atom =
                dfac.getFunction(filterFunct.getFunctionSymbol(), filterFunct.getTerms());
            atoms.add(atom);
          } else {
            throwInvalidFilterExpressionException(filterFunctionStack);
          }
        }

        // Construct the head from the target query.
        List<Function> atomList = targetQuery.getBody();
        // for (Function atom : atomList) {
        Iterator<Function> atomListIter = atomList.iterator();

        while (atomListIter.hasNext()) {
          Function atom = atomListIter.next();
          List<Term> terms = atom.getTerms();
          List<Term> newterms = new LinkedList<Term>();
          for (Term term : terms) {
            newterms.add(updateTerm(term, lookupTable));
          }
          Function newhead = dfac.getFunction(atom.getPredicate(), newterms);
          CQIE rule = dfac.getCQIE(newhead, atoms);
          datalog.appendRule(rule);
        }

      } catch (Exception e) {
        errorMessage.add(
            "Error in mapping with id: "
                + axiom.getId()
                + " \n Description: "
                + e.getMessage()
                + " \nMapping: ["
                + axiom.toString()
                + "]");
      }
    }

    if (errorMessage.size() > 0) {
      StringBuilder errors = new StringBuilder();
      for (String error : errorMessage) {
        errors.append(error + "\n");
      }
      final String msg =
          "There was an error analyzing the following mappings. Please correct the issue(s) to continue.\n"
              + errors.toString();
      RuntimeException r = new RuntimeException(msg);
      throw r;
    }
    return datalog;
  }