Bug 195970 Two issues when evaluate a query inlcuding a subquery[07]
Description: Currently, when evaluating a query which includes a subquery, the query will be evaluated twice. The binding of query will pass to subquery twice. If user write a java script such as new Date() and i++. The result of query will be incorrect. Another issue: when write the report document, the binding of query will be written twice and the performance is not good to evalulate it twice.
data/org.eclipse.birt.data/src/org/eclipse/birt/data/engine/impl/ResultIterator.java
/**
	 * Checks to make sure the iterator has started. Throws exception if it has
	 * not.
	 */
	private void checkStarted( ) throws DataException
	{
		if ( state == NOT_STARTED || state == CLOSED )
		{
			DataException e = new DataException( ResourceConstants.RESULT_CLOSED );
			logger.logp( Level.FINE,
					ResultIterator.class.getName( ),
					"checkStarted",
					"ResultIterator has been closed.",
					e );
			throw e;
		}
	}
	
	/*
	 * Returns the QueryResults of this result iterator. A convenience method
	 * for the API consumer.
	 * 
	 * @see org.eclipse.birt.data.engine.api.IResultIterator#getQueryResults()
	 */
	public IQueryResults getQueryResults( )
	{
		return resultService.getQueryResults( );
	}
	
	/*