code: protected static function upgradeInputScreenMode()
      {
          $objDB = self::DB();
          if (!$objDB->tableExists('tl_metamodel_dca', null, true)) {
              return;
          }
  
          if (!$objDB->fieldExists('mode', 'tl_metamodel_dca')) {
              return;
          }
  
          // Create the fields for grouping and sorting and migrate.
          if (!$objDB->fieldExists('rendermode', 'tl_metamodel_dca')) {
              TableManipulation::createColumn(
                  'tl_metamodel_dca',
                  'rendermode',
                  'varchar(12) NOT NULL default \'\''
              );
          }
  
          $objDB->execute('UPDATE tl_metamodel_dca SET rendermode="flat" WHERE mode IN (0,1,2,3)');
          $objDB->execute('UPDATE tl_metamodel_dca SET rendermode="parented" WHERE mode IN (4)');
          $objDB->execute('UPDATE tl_metamodel_dca SET rendermode="hierarchical" WHERE mode IN (5,6)');
  
          TableManipulation::dropColumn('tl_metamodel_dca', 'mode', true);
      }
docs: Upgrade the input screens.
  
  @return void