I have a many-to-many relationship defined in my Symfony (using doctrine) project between Orders and Upgrades (an Order can be associated with zero or more Upgrades, and an Upgrade can apply to zero or more Orders).

# schema.yml

Order:
  columns:
    order_id: {...}
  relations:
    Upgrades:
      class: Upgrade
      local: order_id
      foreign: upgrade_id
      refClass: OrderUpgrade

Upgrade:
  columns:
    upgrade_id: {...}
  relations:
    Orders:
      class: Order
      local: upgrade_id
      foreign: order_id
      refClass: OrderUpgrade

OrderUpgrade:
  columns:
    order_id: {...}
    upgrade_id: {...}

I want to set up delete cascade behavior so that if I delete an Order or an Upgrade, all of the related OrderUpgrades are deleted. Where do I put onDelete: CASCADE? Usually I would put it at the end of the relations section, but that would seem to imply in this case that deleting Orders would cascade to delete Upgrades. Is Symfony + Doctrine smart enough to know what I'm wanting if I put onDelete: CASCADE in the above relations sections of schema.yml?