Examples of org.teiid.query.sql.util.ValueIterator

org.teiid.query.sql.util.ValueIterator

Interface for interating through Expressions or values. It may return instances of Expression (which then have to be evaluated) or it may return some Object constant value - this should be checked for after calling {@link #next next}

This interface is meant to abstract the details of how the values are stored and retrieved, if they are even stored in memory or not, etc. etc. An implementation instance may or may not be resettable and therefore reusable - see {@link #reset reset}.

    if(leftValue == null) {
            return null;
        }
        Boolean result = Boolean.FALSE;


        ValueIterator valueIter = null;
        if (criteria instanceof SetCriteria) {
          SetCriteria set = (SetCriteria)criteria;
          if (set.isAllConstants()) {
            boolean exists = set.getValues().contains(new Constant(leftValue, criteria.getExpression().getType()));
            if (!exists) {
              if (set.getValues().contains(Constant.NULL_CONSTANT)) {
                return null;
              }
              return criteria.isNegated();
            }
            return !criteria.isNegated();
          }
          valueIter = new CollectionValueIterator(((SetCriteria)criteria).getValues());
        } else if (criteria instanceof DependentSetCriteria){
          ContextReference ref = (ContextReference)criteria;
        ValueIteratorSource vis = (ValueIteratorSource)getContext(criteria).getVariableContext().getGlobalValue(ref.getContextSymbol());
        Set<Object> values;
        try {
          values = vis.getCachedSet(ref.getValueExpression());
        } catch (TeiidProcessingException e) {
          throw new ExpressionEvaluationException(e, e.getMessage());
        }
          if (values != null) {
            return values.contains(leftValue);
          }
          //there are too many values to justify a linear search or holding
          //them in memory
          return true;
        } else if (criteria instanceof SubquerySetCriteria) {
          try {
        valueIter = evaluateSubquery((SubquerySetCriteria)criteria, tuple);
      } catch (TeiidProcessingException e) {
        throw new ExpressionEvaluationException(e, e.getMessage());
      }
        } else {
          throw new AssertionError("unknown set criteria type"); //$NON-NLS-1$
        }
        while(valueIter.hasNext()) {
            Object possibleValue = valueIter.next();
            Object value = null;
            if(possibleValue instanceof Expression) {
          try {
            value = evaluate((Expression) possibleValue, tuple);
          } catch(ExpressionEvaluationException e) {

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        Boolean result = Boolean.FALSE;
        if (criteria.getPredicateQuantifier() == SubqueryCompareCriteria.ALL){
            result = Boolean.TRUE;
        }


        ValueIterator valueIter;
    try {
      valueIter = evaluateSubquery(criteria, tuple);
    } catch (TeiidProcessingException e) {
      throw new ExpressionEvaluationException(e, e.getMessage());
    }
        while(valueIter.hasNext()) {
            Object value = valueIter.next();


            if(value != null) {
              int compare = compareValues(leftValue, value);
                // Compare two non-null values using specified operator
                switch(criteria.getOperator()) {

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    }


    public boolean evaluate(ExistsCriteria criteria, List<?> tuple)
        throws BlockedException, TeiidComponentException, ExpressionEvaluationException {


        ValueIterator valueIter;
    try {
      valueIter = evaluateSubquery(criteria, tuple);
    } catch (TeiidProcessingException e) {
      throw new ExpressionEvaluationException(e, e.getMessage());
    }
        if(valueIter.hasNext()) {
            return !criteria.isNegated();
        }
        return criteria.isNegated();
    }

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  private Object evaluate(ScalarSubquery scalarSubquery, List<?> tuple)
      throws ExpressionEvaluationException, BlockedException, TeiidComponentException {
    
      Object result = null;
        ValueIterator valueIter;
    try {
      valueIter = evaluateSubquery(scalarSubquery, tuple);
    } catch (TeiidProcessingException e) {
      throw new ExpressionEvaluationException(e, e.getMessage());
    }
      if(valueIter.hasNext()) {
          result = valueIter.next();
          if(valueIter.hasNext()) {
              // The subquery should be scalar, but has produced
              // more than one result value - this is an exception case
              throw new ExpressionEvaluationException("ERR.015.006.0058", QueryPlugin.Util.getString("ERR.015.006.0058", scalarSubquery.getCommand())); //$NON-NLS-1$ //$NON-NLS-2$
          }
      }

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              }
              dvs = new DependentValueSource(sortUtility.sort());
              for (SetState setState : dependentSetStates) {
                    setState.valueIterator = dvs.getValueIterator(setState.valueExpression);
                    if (setState.maxNdv > 0 && setState.maxNdv < dvs.getTupleBuffer().getRowCount()) {
                      ValueIterator vi = dvs.getValueIterator(setState.valueExpression);
                      Comparable last = null;
                      int distinctCount = 0;
                      while (vi.hasNext()) {
                        Comparable next = (Comparable) vi.next();
                        if (last == null || next.compareTo(last) != 0) {
                          distinctCount++;
                        }
                        last = next;
                      }

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Related Classes of org.teiid.query.sql.util.ValueIterator

org.teiid.query.eval.Evaluator

org.teiid.query.processor.relational.DependentCriteriaProcessor$TupleState

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