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
} );
	}
	/**
	 * Insert a text string into the text area
	 * 
	 * @param text
	 */
	private void insertText( String text )
	{
		if ( text == null )
			return;
		StyledText textWidget = viewer.getTextWidget( );
		int selectionStart = textWidget.getSelection( ).x;
		textWidget.insert( text );
		textWidget.setSelection( selectionStart + text.length( ) );
		textWidget.setFocus( );
	}
	
	/**
	 * Creates the textual query editor 
	 * @param parent
	 */
	private void createTextualQueryComposite( Composite parent )
	{
		
        Composite composite = new Composite( parent, SWT.FILL
				| SWT.LEFT_TO_RIGHT );
        GridLayout layout = new GridLayout();
        layout.numColumns = 1;
        composite.setLayout(layout);