Ash Elixir•3d ago

Sorting on the first relationship in an aggregate

I want to do an aggregate over a m2m table where the order is important, so I write the code below but whatever I do I can't seem to sort on the first table. Should I be able to do that?

  aggregates do
    list :phone_numbers_list, [:some_many_to_one_table, :user], :phone_number do
      public? true
      sort expr(some_many_to_many_table.order)
    end
  end

  aggregates do
    list :phone_numbers_list, [:some_many_to_one_table, :user], :phone_number do
      public? true
      sort expr(some_many_to_many_table.order)
    end
  end

Solution:

tldr: Calculations ❤️ The solution was to use a calculation on :some_many_to_one_table that got the phone number: ```elixir...

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5 Replies

Solution

Andreas Ekeroot @ work•3d ago

tldr: Calculations ❤️ The solution was to use a calculation on :some_many_to_one_table that got the phone number:

  calculations do
    calculate :phone_number, :string, expr(some_many_to_one_table.phone_number), public?: true
  end

  calculations do
    calculate :phone_number, :string, expr(some_many_to_one_table.phone_number), public?: true
  end

And then create another calculation on the first resource:

    calculate :phone_numbers_list,
              {:array, :string},
              expr(list(some_many_to_one_table, query: [sort: :order], field: :phone_number))

    calculate :phone_numbers_list,
              {:array, :string},
              expr(list(some_many_to_one_table, query: [sort: :order], field: :phone_number))

And then I could load everything and produce a super pretty query with the best type annotation.

Ash.load!(clock, :phone_numbers_list, actor: context.actor) |> IO.inspect()

Ash.load!(clock, :phone_numbers_list, actor: context.actor) |> IO.inspect()

$1::text[])::text[]::text[]

$1::text[])::text[]::text[]

ZachDaniel•3d ago

Yeah I thought we fixed the double type casting but must not have

Andreas Ekeroot @ workOP•3d ago

Oh, does double type casting do anything? Except for making me happy. 🙂

ZachDaniel•3d ago

double type casting can have performance impacts where it gets confused about the index to use I think? Either way it would probably end up as something like:

$1::text[])::text[]

$1::text[])::text[]

Andreas Ekeroot @ workOP•3d ago

Got it! It's always the risk of making the query planner confused that makes me worried when interacting with databases.

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Sorting on the first relationship in an aggregate

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