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.tests/test/org/eclipse/birt/report/model/api/ReportItemHandleTest.java
{
			tableHandle.addColumnBinding( col2, true );
			fail( );
		}
		catch ( SemanticException e )
		{
			assertEquals( PropertyValueException.DESIGN_EXCEPTION_VALUE_EXISTS,
					e.getErrorCode( ) );
		}
		col = StructureFactory.createComputedColumn( );
		col.setName( "CUSTOMERNUMBER" ); 
		col.setExpression( "dataSetRow[\"CUSTOMERNUMBER_TEST\"]" ); 
		try
		{
			tableHandle.addColumnBinding( col, true );
			fail( );
		}
		catch ( SemanticException e )
		{
			assertEquals( PropertyValueException.DESIGN_EXCEPTION_VALUE_EXISTS,
					e.getErrorCode( ) );
		}
		col = StructureFactory.createComputedColumn( );
		col.setName( "CUSTOMERNUMBER_TEST" ); 
		col.setExpression( "dataSetRow[\"CUSTOMERNUMBER\"]" ); 
		tableHandle.addColumnBinding( col, true );
		col = (ComputedColumn) ( (ComputedColumnHandle) tableHandle
				.columnBindingsIterator( ).next( ) ).getStructure( );
		
		PropertyHandle propertyHandle = tableHandle