Bug 200286 [Regression] Data set editor size is not correct [07]
data/org.eclipse.birt.report.data.oda.jdbc.ui/src/org/eclipse/birt/report/data/oda/jdbc/ui/editors/SQLDataSetEditorPage.java
* @return The Type of the object selected in the type combo ( Can be one of the following )
	 *   1) TABLE
	 *   2) VIEW
	 *   3) ALL
	 */
	private String getSelectedDbType( )
	{
		IStructuredSelection selection = (IStructuredSelection) filterComboViewer.getSelection( );
		String type = DbType.ALL_STRING;
		if ( selection != null && selection.getFirstElement( ) != null )
		{
			DbType dbType = (DbType) selection.getFirstElement( );
			switch ( dbType.getType( ) )
			{
				case DbType.TABLE_TYPE :
					type = DbType.TABLE_STRING;
					break;
				case DbType.VIEW_TYPE :
					type = DbType.VIEW_STRING;
					break;
				case DbType.PROCEDURE_TYPE :
					type = DbType.PROCEDURE_STRING;
					break;
			}
		}
		return type;
	}
	/**
	 * @param item A tree Item which has to be tested
	 * @return if the TreeItem represents a Schema node