Bug 161191 Null is inserted when drag columns to query text with ctrl key pressed
Description: Null is inserted when drag columns to query text with ctrl key pressed Steps to reproduce: 1. New a data source. 2. New a dataset. 3. Press and hold ctrl key, select OFFICECODE and CITY columns, drag to query text. Expected result: "CLASSICMODELS.OFFICES.OFFICECODE,CLASSICMODELS.OFFICES.CITY" is inserted in query text. Actual result: "null,CLASSICMODELS.OFFICES.OFFICECODE,CLASSICMODELS.OFFICES.CITY" is inserted
data/org.eclipse.birt.report.data.oda.jdbc.ui/src/org/eclipse/birt/report/data/oda/jdbc/ui/editors/SQLDataSetEditorPage.java
selectionMac = availableDbObjectsTree.getSelection( );
				if ( selection.length > 0 )
				{
					if ( selection[0].getData( ) instanceof DbObject )
					{
						if ( ( (DbObject) selection[0].getData( ) ).getType( ) == DbObject.PROCEDURE_TYPE )
						{
							event.doit = false;
							return;
						}
					}
					else if ( selection[0].getData( ) instanceof ProcedureParameter )
					{
						event.doit = false;
						return;
					}
				}
				else if ( selection.length <= 0
						|| selection[0].getData( ) == null )
				{
					event.doit = false;
					return;
				}
			}
			public void dragSetData( DragSourceEvent event )
			{
				if ( TextTransfer.getInstance( )
						.isSupportedType( event.dataType ) )
				{
					populateEventData( event );