Bug 207564 Column sorting based on data type
Only string sorting happens when a column is selected in preview result page of DataSet Editor irrespective of type of data shown in that column. I'd like to be able to sort the data based on its datatype when a column is selected.
UI/org.eclipse.birt.report.designer.ui/src/org/eclipse/birt/report/designer/data/ui/util/DataSetProvider.java
dataSetDesign.getFilters( ).clear( );
		}
		if ( !( dataSet instanceof JointDataSetHandle ) )
		{
			IBaseDataSourceDesign dataSourceDesign = session.getModelAdaptor( )
					.adaptDataSource( dataSet.getDataSource( ) );
			session.defineDataSource( dataSourceDesign );
		}
		if ( dataSet instanceof JointDataSetHandle )
		{
			defineSourceDataSets( session, dataSet, dataSetDesign );
		}
		session.defineDataSet( dataSetDesign );
		return dataSetDesign;
	}
	
	/**
	 * @param dataSet
	 * @param dataSetDesign
	 * @throws BirtException
	 */
	private void defineSourceDataSets( DataRequestSession session, DataSetHandle dataSet,
			IBaseDataSetDesign dataSetDesign ) throws BirtException
	{
		List dataSets = dataSet.getModuleHandle( ).getAllDataSets( );
		for ( int i = 0; i < dataSets.size( ); i++ )
		{
			DataSetHandle dsHandle = (DataSetHandle) dataSets.get( i );
			if ( dsHandle.getName( ) != null )
			{