Rails - Nested includes on Active Records?

Question

I have a list of events that I fetch. I'm trying to include every user associated to this event and every profile associated to each user. The Users get included but not their profiles.

How Would i do this

Event.includes(:users [{profile:}])

The docs don't seem to be clear: http://guides.rubyonrails.org/active_record_querying.html

score 495 · Accepted Answer · edited Dec 24 '21 at 13:29

495

I believe the following should work for you.

Event.includes(users: :profile)

If you want to include an association (we'll call it C) of an already included association (we'll call it B), you'd use the syntax above. However, if you'd like to include D as well, which is also an association of B, that's when you'd use the array as given in the example in the Rails Guide.

A.includes(bees: [
  :cees, 
  :dees
])

You could continue to nest includes like that (if you actually need to). Say that A is also associated with Z, and that C is associated to E and F.

A.includes({
  bees: [{
    cees: [:ees, :effs]
  }, :dees]
}, :zees)

And for good fun, we'll also say that E is associated to J and X, and that D is associated to Y.

A.includes({
  bees: [{
      cees: [{
        ees: [:jays, :exes]
      }, :effs]
    },
    {
      dees: :wise
    }
  ]
}, :zees)

edited Dec 24 '21 at 13:29

duhaime

25,611
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answered Jun 24 '14 at 22:59

Joe Kennedy

9,365
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13

How would you add conditions for the included modules..? :) – Arup Rakshit May 29 '15 at 12:09
1

how to add there a order? – Florian Widtmann Jan 12 '16 at 07:49
1

In the above, we're assuming an event has many users and a user has many profiels right? – Jwan622 Sep 20 '17 at 15:32
12

This is one of those magical answers that I have found multiple times years apart and saves my ass every time. This is what the docs should look like – Andrew May 31 '18 at 11:33
2

To make this guide the most exhausting one: `A.includes( { bees: { cees: {:dees, :ees} } })` - for the russian doll like construction (i.e. A includes b, which includes c... and so on) – Alexander Gorg Mar 03 '19 at 17:44
6

to add conditions `A.includes(bees: :cees).where(bees: { cees: { flagged: false }}).order("a.bees DESC").order("a.cees ASC")` – Fabrizio Bertoglio Nov 11 '19 at 05:06

score 23 · Answer 2 · answered Jul 03 '19 at 23:34

Please refer to Joe Kennedy's solution.

Here's a more readable example (for future me).

includes(
  :product,
  :package, {
    campaign: [
      :external_records,
      { account: [:external_records] },
      { agency: [:external_records] },
      :owner,
      :partner,
    ]
  }
)

score 16 · Answer 3 · answered Feb 01 '17 at 20:41

16

If anyone is doing a respond_to block to generate nested json, you can do something like:

respond_to do |f|
  f.json do
    render json: event.to_json(include: {users: {include: :profile} }), status: :ok
  end
end

answered Feb 01 '17 at 20:41

Blaskovicz

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1

I think you mean `as_json` -- otherwise this renders the JSON string. – Meekohi Apr 05 '17 at 15:48

Rails - Nested includes on Active Records?

3 Answers3

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