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
/**
	 * get column data by data set handle
	 * @param dataSet
	 * @param refresh
	 * @return
	 */
	public DataSetViewData[] getColumns( DataSetHandle dataSet, boolean refresh )
	{
		return getColumns( dataSet, refresh, true, false );
	}
	/**
	 * 
	 * @param dataSet
	 * @param refresh
	 * @param useColumnHints
	 *            Only applicable if the list is refreshed.
	 * @return
	 */
	public DataSetViewData[] getColumns( DataSetHandle dataSet,
			boolean refresh, boolean useColumnHints,
			boolean suppressErrorMessage )
	{
		if ( dataSet == null )
		{
			return new DataSetViewData[0];
		}
		DataSetViewData[] columns = null;
		try
		{
			DataSessionContext context = new DataSessionContext( DataSessionContext.MODE_DIRECT_PRESENTATION,