function bat_event_update_8002 in Booking and Availability Management Tools for Drupal 8
Drop old "start" and "end" columns on event table.
File
- modules/bat_event/ bat_event.install, line 70 
- Sets up the base table for our entity and a table to store information about the entity types.
Code
function bat_event_update_8002() {
  Database::getConnection()
    ->schema()
    ->dropField('event', 'start');
  Database::getConnection()
    ->schema()
    ->dropField('event', 'end');
}