Bug 191685 [regression]Set default value doesn't work in Report Parameter[0705]
UI/org.eclipse.birt.report.designer.ui/src/org/eclipse/birt/report/designer/ui/dialogs/ParameterDialog.java
String columnBindingName = "_$_COLUMNBINDINGNAME_$_";
			query.addResultSetExpression( columnBindingName, expression );
			
			IPreparedQuery preparedQuery = engine.prepare( (IQueryDefinition) query );
			IQueryResults results = preparedQuery.execute( null );
			if ( results != null )
			{
				IResultIterator iter = results.getResultIterator( );
				if ( iter != null )
				{
					DateFormatter formatter = new DateFormatter( STANDARD_DATE_TIME_PATTERN,
							ULocale.US );
					while ( iter.next( ) )
					{
						String result = null;
						if ( DesignChoiceConstants.COLUMN_DATA_TYPE_DATETIME.equals( getSelectedDataType( ) ) )
						{
							result = formatter.format( iter.getDate( columnBindingName ) );
						}
						else
						{
							result = iter.getString( columnBindingName );
						}
						if ( !StringUtil.isBlank( result )
								&& !valueList.contains( result ) )
						{
							valueList.add( result );
						}
					}
				}