Bug 118592 Report error
please see attached design file.
data/org.eclipse.birt.data/src/org/eclipse/birt/data/engine/impl/ResultIterator.java
String[] columnNames, int i ) throws BirtException
	{
		Object fieldValue = odiResult.getCurrentResult( )
				.getFieldValue( columnNames[i] );
		boolean retValue = false;
		if ( fieldValue == groupKeyValues[i] )
		{
			retValue = true;
		}
		else if ( fieldValue != null && groupKeyValues[i] != null )
		{
			if ( fieldValue.getClass( ).equals( groupKeyValues[i].getClass( ) ) )
			{
				retValue = fieldValue.equals( groupKeyValues[i] );
			}
			else
			{
				Object convertedOb = DataTypeUtil.convert( groupKeyValues[i],
						fieldValue.getClass( ) );
				retValue = fieldValue.equals( convertedOb );
			}
		}
		return retValue;
	}
	/**
	 * The method which extracts column name from group definition.
	 * 
	 * @param group
	 * @return
	 */