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
public String getOnCreate( )
	{
		return getStringProperty( IReportItemModel.ON_CREATE_METHOD );
	}
	/**
	 * Sets the script executed when the element is created in the Factory.
	 * Called after the item is created, but before the item is saved to the
	 * report document file.
	 * 
	 * @param value
	 *            the script to set
	 * @throws SemanticException
	 *             if the property is locked.
	 */
	public void setOnCreate( String value ) throws SemanticException
	{
		setProperty( IReportItemModel.ON_CREATE_METHOD, value );
	}
	/**
	 * Returns the script executed when the element is prepared for rendering in
	 * the Presentation engine.
	 * 
	 * @return the script that executes
	 */
	public String getOnRender( )
	{
		return getStringProperty( IReportItemModel.ON_RENDER_METHOD );
	}
	/**
	 * Sets the script executed when the element is prepared for rendering in