getTable('talk_thread_attendees'); if ($table->hasUniqueConstraint('tta_thread_attendee')) { $table->removeUniqueConstraint('tta_thread_attendee'); } if (!$table->hasUniqueConstraint('tta_throom_attendee')) { $table->addUniqueIndex(['thread_id', 'room_id', 'actor_type', 'actor_id'], 'tta_throom_attendee'); } return null; } }