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
{
		int leftWidth = sashForm.getChildren( )[0].computeSize( SWT.DEFAULT,
				SWT.DEFAULT ).x;
		int totalWidth = sashForm.computeSize( SWT.DEFAULT, SWT.DEFAULT ).x;
		if ( (double) leftWidth / (double) totalWidth > 0.4 )
		{
			
			sashForm.setWeights( new int[]{
					40, 60
			} );
		}
		else
		{
			sashForm.setWeights( new int[]{
					leftWidth, totalWidth - leftWidth
			} );
		}
	}
	/**
	 * 
	 * @param group
	 */
	private void setupIdentifierQuoteStringCheckBox( Group group )
	{
		GridData layoutData = new GridData( GridData.FILL_HORIZONTAL );
		layoutData.horizontalSpan = 3;
		identifierQuoteStringCheckBox = new Button( group, SWT.CHECK );
		identifierQuoteStringCheckBox.setText( JdbcPlugin.getResourceString( "tablepage.button.dnd" ) ); 
		identifierQuoteStringCheckBox.setSelection( false );
		identifierQuoteStringCheckBox.setLayoutData( layoutData );