CODEWITHSUNDEEP
ruby-on-railsrubymongoid
Peter R
Peter R

Reputation: 3516

How to look up associated models by an attribute hash

FYI this project uses Mongo/Mongoid

Lets say I have models A, B, C, and D. A has_many Bs has_many Cs has_many Ds.

each has an attribute 'name' which is unique in it's association tree, but not necessarily in the whole model class.

If I had a hash like this:

{a: "name1", b: "name2", c: "name3"}

or 

{a: "name2", b: "name2", c: "name3", d: "name4"}

How can I find the last model in the hash? Essentially (although it would need to be dynamic to hash size):

@item = A.where(name: "name1").first
        .Bs.where(name: "name2").first
        .Cs.where(name: "name3").first

Upvotes: 0

Views: 51

Answers (1)

bunty
bunty

Reputation: 1098

You can do with,

@item = A.where(name: "name1").first
@item = @item ? @item.Bs.where(name: "name2").first : Bs.where(name: "name2").first
@item = @item ? @item.Cs.where(name: "name3").first : Cs.where(name: "name3").first
@item = @item ? @item.Ds.where(name: "name4").first : Ds.where(name: "name4").first

Upvotes: 0

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