Bug 186742 [Smoke]Can not create a joint dataset[07]
Description: [Smoke]Can not create a joint dataset[07] Build number: 2.2.0.v20070514-0630 Steps to reproduce: 1, New two datasets ds1 and ds2 2, New a joint dataset 3, Select ds1 as the left dataset Expected result: The dataset can be selected successfully and show all the columns of ds1 Actual result: Error occurs after select the ds1 and no columns list Error log: java.lang.ClassCastException: org.eclipse.jface.wizard.WizardDialog at org.eclipse.birt.report.designer.data.ui.dataset.JointDataSetPage.selectionChanged(JointDataSetPage.java:553) at org.eclipse.jface.viewers.Viewer$2.run(Viewer.java:162) at org.eclipse.core.runtime.SafeRunner.run(SafeRunner.java:37) at org.eclipse.core.runtime.Platform.run(Platform.java:850) at org.eclipse.ui.internal.JFaceUtil$1.run(JFaceUtil.java:46) at org.eclipse.jface.util.SafeRunnable.run(SafeRunnable.java:193) at org.eclipse.jface.viewers.Viewer.fireSelectionChanged(Viewer.java:160) at org.eclipse.jface.viewers.StructuredViewer.updateSelection(StructuredViewer.java:2039) at org.eclipse.jface.viewers.StructuredViewer.handleSelect(StructuredViewer.java:1138) at org.eclipse.jface.viewers.StructuredViewer$4.widgetSelected(StructuredViewer.java:1164) at org.eclipse.jface.util.OpenStrategy.fireSelectionEvent(OpenStrategy.java:227)
UI/org.eclipse.birt.report.designer.ui/src/org/eclipse/birt/report/designer/data/ui/util/DataSetProvider.java
canExecute = ( queryTxt != null && queryTxt.trim( )
							.length( ) > 0 );
				}
				if ( canExecute )
				{
					IQueryResults results = execute( dataSet,
							useColumnHints,
							true,
							1,
							session );
					if ( results != null )
					{
						results.close( );
					}
					
					columns = (DataSetViewData[]) htColumns.get( dataSet );
				}
				session.shutdown( );
			}
			catch ( BirtException e )
			{
				if ( !suppressErrorMessage )
				{
					ExceptionHandler.handle( e );
				}
			}
		}
		
		
		if ( columns == null )