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
* 
	 * @param dataSet
	 * @return
	 * @throws BirtException
	 */
	public IPreparedQuery prepareQuery( DataSetHandle dataSet,
			IQueryDefinition query ) throws BirtException
	{
		DataRequestSession session = getDataRequestSession( dataSet );
		getDataSetDesign( dataSet, true, true );
		return session.prepare( query, null );
	}
	
	/**
	 * 
	 * @param dataSet
	 * @return
	 * @throws BirtException
	 */
	public IPreparedQuery prepareQuery( DataSetHandle dataSet,
			IQueryDefinition query, boolean useColumnHints, boolean useFilters )
			throws BirtException
	{
		DataRequestSession session = getDataRequestSession( dataSet );
		getDataSetDesign( dataSet, useColumnHints, useFilters );
		return session.prepare( query, null );
	}
	
	/**
	 * Gets prepared query, given Data set, Parameter binding, and