Bug 141950 Selection of select value in data set filter is error
Details: Selection of select value in data set filter is error Step: 1.New a report design. 2.Create a sample datasource and dataset. 3.Switch to filter. 4.Select a value in expression. 5.Drop the list of the value1 and select <select value...> Actual result: No value is appear and pop up an error. It said that "An expression has not been set"
UI/org.eclipse.birt.report.designer.ui/src/org/eclipse/birt/report/designer/data/ui/util/DataSetProvider.java
* @return
	 * @throws BirtException
	 */
	public IPreparedQuery prepareQuery( DataSetHandle dataSet )
			throws BirtException
	{
		DataRequestSession session = getDataRequestSession( dataSet );
		IBaseDataSetDesign dataSetDesign = getDataSetDesign( dataSet,
				false,
				false );
		QueryDefinition queryDefn = getQueryDefinition( dataSetDesign, -1 );
		return session.prepare( queryDefn, null );
	}
	
	/**
	 * 
	 * @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 );
	}
	
	/**
	 * Gets prepared query, given Data set, Parameter binding, and