Bug 135778 There is an error when the data item has no binding data set
Data item can have no binding data set, if it happens, it indicates it only use the basic Java Script function such as new Date(). At this moment, the data of data item is not stored in report document by DtE, which only supports these data items which has binding data set.
data/org.eclipse.birt.data/src/org/eclipse/birt/data/engine/impl/PreparedDummyQuery.java
this.checkOpened( );
			if ( groupLevel > 0 )
				throw new DataException( "invalid group level value" );
		}
		/*
		 * @see org.eclipse.birt.data.engine.api.IResultIterator#getStartingGroupLevel()
		 */
		public int getStartingGroupLevel( ) throws BirtException
		{
			this.checkOpened( );
			return 0;
		}
		/*
		 * @see org.eclipse.birt.data.engine.api.IResultIterator#getEndingGroupLevel()
		 */
		public int getEndingGroupLevel( ) throws BirtException
		{
			this.checkOpened( );
			return 0;
		}
		/*
		 * @see org.eclipse.birt.data.engine.api.IResultIterator#getSecondaryIterator(java.lang.String, org.mozilla.javascript.Scriptable)
		 */
		public IResultIterator getSecondaryIterator( String subQueryName,
				Scriptable scope ) throws BirtException
		{
			this.checkOpened( );
			return null;
		}
		/*