Bug 168026 Still use the existing data binding even though the aggregate is different
I had a table in which a data binding which aggregates on a group. When I insert a new data item in the report, although the expressions are same, it aggregates on All, then it refered to the existing data binding. The expected behavior would be a new data binding is created with different aggregates.
model/org.eclipse.birt.report.model/src/org/eclipse/birt/report/model/api/ReportItemHandle.java
setStringProperty( DATA_SET_PROP, null );
		else
		{
			ModuleHandle moduleHandle = handle.getRoot( );
			String valueToSet = handle.getName( );
			if ( moduleHandle instanceof LibraryHandle )
			{
				String namespace = ( (LibraryHandle) moduleHandle )
						.getNamespace( );
				valueToSet = StringUtil.buildQualifiedReference( namespace,
						handle.getName( ) );
			}
			setStringProperty( IReportItemModel.DATA_SET_PROP, valueToSet );
		}
	}
	/**
	 * Gets a handle to deal with the item's x (horizontal) position.
	 * 
	 * @return a DimensionHandle for the item's x position.
	 */
	public DimensionHandle getX( )
	{
		return super.getDimensionProperty( IReportItemModel.X_PROP );
	}
	/**
	 * Gets a handle to deal with the item's y (vertical) position.
	 * 
	 * @return a DimensionHandle for the item's y position.
	 */
	public DimensionHandle getY( )