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ruby-on-railsrubydestroy

Null and Id in Rails on Destroy

Is there a way to set a sort of dependent:destroy that will null an id but not destroy the record? For instance, I have a Order model that contains information about a patron's orders. I also have a Patron model that contains info about the patron. When I destroy a patron, I'd like all the ids for that patron (patron_id) in Order to be null now, so as to avoid weird mixups with new patrons, should that id be reused. However, I still want to keep the Order record for analysis of what was ordered the most, etc. Is there a relationship that defines this?

Example:

Order

  • order_id
  • patron_id
  • order_info

Patron

  • patron_id
  • patron_name

A patron has_many: orders. An order belongs_to: patron Lets say I have patrons [{1,'Bob'},{2,'Sally'}] And orders [{1,2,'Cake'},{2,2,'Screwdriver'},{3,1,'Ham'}] Then I destroy sally, making patrons [{1,'Bob'}]. I'd want orders to be [{1,null,'Cake'},{2,null,'Screwdriver'},{3,1,'Ham'}]

How would I do this?

Solution

  • You need to use option nullify

    has_many :orders, dependent: :nullify

    see more details in chapter 4.2.2.4 :dependent