CODEWITHSUNDEEP
elixirectopreload
Thib
Thib

Reputation: 193

How to filter preloaded records by query

I am listing a list of records (Packs).

Those Packs are linked to items through a many to many relation :

When I am listing the packs, i'd like to preload their active items

def list_packs(params) do
  packs = Pack
    |> preload_active_items()
    |> Repo.all()
    |> Repo.preload([:classroom, [packlanguages: :language]])
end

defp preload_active_items(query) do
  query
    |> join(:left, [pack], _ in assoc(pack, :packitems))
    |> join(:left, [_, pi], _ in assoc(pi, :item))
    |> where([..., i], i.active == true)
    |> preload([_, pi, i], [packitems: {pi, item: i}])
    # |> preload([_, pi, i], [packitems: {pi, item: ^from(i, where: i.active == true)}])
end

Everything is working fine (I retrieve the packs and their preloaded items), but I get the packs filtered on those having an active item.

I tried to replace the where clause by the dashed line but the syntax is not correct.

Any idea ?

Upvotes: 2

Views: 1167

Answers (1)

Thib
Thib

Reputation: 193

I found my way finally : 

def list_packs(params) do
  pi_query = from pi in PackItem,
    join: i in assoc(pi, :item),
    where: i.active == true
  packs = Pack
    |> Repo.all()
    |> Repo.preload([:classroom, [packlanguages: :language, packitems: pi_query]])
end

Upvotes: 5

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