Bug 192083 [regression]DataException when preview attached xtab report.[1102]
data/org.eclipse.birt.report.data.adapter/src/org/eclipse/birt/report/data/adapter/impl/DataRequestSessionImpl.java
Iterator columnBindings = bindings.iterator( ); 
		while ( columnBindings != null && columnBindings.hasNext( ) )
		{
			IComputedColumn column = this.modelAdaptor.adaptComputedColumn( (ComputedColumnHandle) columnBindings.next( ) );
			if ( column.getName( ).equals( boundColumnName ) )
			{
				ScriptExpression sxp = (ScriptExpression) column.getExpression( );
				if ( ExpressionUtil.hasAggregation( sxp.getText( ) ) )
				{
					return true;
				}
				else
				{
					Iterator columnBindingNameIt = ExpressionUtil.extractColumnExpressions( sxp.getText( ) )
							.iterator( );
					while ( columnBindingNameIt.hasNext( ) )
					{
						IColumnBinding columnBinding = (IColumnBinding)columnBindingNameIt.next( );
						
						if ( referToAggregation( bindings,
								columnBinding.getResultSetColumnName( ) ) )
							return true;
					}
				}
			}
		}
		return false;
	}
	/*
	 * (non-Javadoc)