AF
Ash Framework•3w ago
ajst7les

manage_relationship not creating many-to-many join records

I'm having trouble getting manage_relationship to work with a many-to-many relationship where the destination resource uses a non-standard primary key. Setup I have a many-to-many relationship between Device and Pass through a DeviceRegistration join table: - Device: Standard resource with uuid_primary_key :id - Pass: Uses uuid_primary_key :serial_number (not :id) - DeviceRegistration: Join table with device_id and serial_number fields Resource Configurations Device Resource 
defmodule MyApp.Device do
  use Ash.Resource

  actions do
    create :register do
      primary? true
      accept [:apple_device_id, :push_token]
      argument :passes, {:array, :uuid}, allow_nil?: true

      change manage_relationship(:passes, type: :append, value_is_key: :serial_number)

      upsert? true
      upsert_identity :unique_device_id
    end
  end

  relationships do
    many_to_many :passes, MyApp.Pass do
      through MyApp.DeviceRegistration
      source_attribute_on_join_resource :device_id
      destination_attribute :serial_number
      destination_attribute_on_join_resource :serial_number
    end
  end
end
defmodule MyApp.Device do
  use Ash.Resource

  actions do
    create :register do
      primary? true
      accept [:apple_device_id, :push_token]
      argument :passes, {:array, :uuid}, allow_nil?: true

      change manage_relationship(:passes, type: :append, value_is_key: :serial_number)

      upsert? true
      upsert_identity :unique_device_id
    end
  end

  relationships do
    many_to_many :passes, MyApp.Pass do
      through MyApp.DeviceRegistration
      source_attribute_on_join_resource :device_id
      destination_attribute :serial_number
      destination_attribute_on_join_resource :serial_number
    end
  end
end
3 Replies
ajst7les
ajst7lesOP•3w ago
Pass Resource 
defmodule MyApp.Pass do
  use Ash.Resource

  attributes do
    uuid_primary_key :serial_number  # <-- Non-standard primary key
    # ... other attributes
  end

  relationships do
    many_to_many :devices, MyApp.Device do
      through MyApp.DeviceRegistration
      source_attribute_on_join_resource :serial_number
      destination_attribute :id
      destination_attribute_on_join_resource :device_id
    end
  end
end
defmodule MyApp.Pass do
  use Ash.Resource

  attributes do
    uuid_primary_key :serial_number  # <-- Non-standard primary key
    # ... other attributes
  end

  relationships do
    many_to_many :devices, MyApp.Device do
      through MyApp.DeviceRegistration
      source_attribute_on_join_resource :serial_number
      destination_attribute :id
      destination_attribute_on_join_resource :device_id
    end
  end
end
DeviceRegistration Join Resource 
defmodule MyApp.DeviceRegistration do
  use Ash.Resource

  actions do
    create :create do
      primary? true
      accept [:device_id, :serial_number]
    end
  end

  attributes do
    uuid_primary_key :id
    timestamps()
  end

  relationships do
    belongs_to :device, MyApp.Device do
      allow_nil? false
    end

    belongs_to :pass, MyApp.Pass do
      source_attribute :serial_number
      destination_attribute :serial_number
      allow_nil? false
    end
  end

  identities do
    identity :unique_registration, [:device_id, :serial_number]
  end
end
defmodule MyApp.DeviceRegistration do
  use Ash.Resource

  actions do
    create :create do
      primary? true
      accept [:device_id, :serial_number]
    end
  end

  attributes do
    uuid_primary_key :id
    timestamps()
  end

  relationships do
    belongs_to :device, MyApp.Device do
      allow_nil? false
    end

    belongs_to :pass, MyApp.Pass do
      source_attribute :serial_number
      destination_attribute :serial_number
      allow_nil? false
    end
  end

  identities do
    identity :unique_registration, [:device_id, :serial_number]
  end
end
The Problem When I try to create a device with passes: 
{:ok, device} = Ash.create(MyApp.Device, %{
  apple_device_id: "device123",
  push_token: "token123"
}, passes: [pass.serial_number])
{:ok, device} = Ash.create(MyApp.Device, %{
  apple_device_id: "device123",
  push_token: "token123"
}, passes: [pass.serial_number])
The device gets created successfully, but no join records are created in the DeviceRegistration table. When I load the relationship: 
loaded_device = Ash.load!(device, :passes)
assert length(loaded_device.passes) == 1  # FAILS - passes is []
loaded_device = Ash.load!(device, :passes)
assert length(loaded_device.passes) == 1  # FAILS - passes is []
ZachDaniel
ZachDaniel•3w ago
      change manage_relationship(:passes, type: :append, value_is_key: :serial_number, debug?: true)
      change manage_relationship(:passes, type: :append, value_is_key: :serial_number, debug?: true)
try adding debug? true and seeing what is logged Are you sure that no join records are created? i.e Ash.count!(JoinResource) == 0?
ajst7les
ajst7lesOP•3w ago
Thanks I solved it with debug was a silly typo in the execution flow on my side that went unnoticed!!! Thanks for being so responsive!

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