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/PreparedSubquery.java
{
		private IResultIterator parentIterator;
		
		/**
		 * @param parentIterator
		 */
		public SubQueryExecutor( IResultIterator parentIterator )
		{	
			super( preparedQuery.getSharedScope( ),
					preparedQuery.getBaseQueryDefn( ),
					preparedQuery.getAggrTable( ),
					session);
			
			this.parentIterator = parentIterator;
			this.setParentExecutorHelper( parentIterator.getExecutorHelper( ) );
		}
		
		/*
		 * @see org.eclipse.birt.data.engine.impl.PreparedQuery.Executor#createOdiDataSource()
		 */
		protected IDataSource createOdiDataSource( )
		{
			
			return null;
		}
		
		/*
		 * @see org.eclipse.birt.data.engine.impl.PreparedQuery.Executor#findDataSource()
		 */