Hello! I have 2 schemas: Asset and File. # asset schema has_many :files, File # file schema belongs_to :asset, Asset So it looks like: %Asset{ __meta__: #Ecto.Schema.Metadata<:loaded, "assets">, id: 1, name: "name", files: [] } Each time i need to update my asset.files (for exampl…

Two options. Either just do inserts directly to Files that include asset_id, or if you will always have the entire collection of files loaded, you can use nested changesets. So in your Asset changeset, you will have a function: cast_assoc(:files, required: false, with: &File.changeset/2) When you …

Ok, now i have this: params = %{ files: [ %{filename: "name1"}, %{filename: "name2"} ] } asset |> Repo.preload(:files) |> Ecto.Changeset.cast(params, []) |> Ecto.Changeset.cast_assoc(:files) # works o only at first time |> Repo.update So first time it works well, but second time it …

[image] helicon: So first time it works well, but second time it raises exception: ** (RuntimeError) you are attempting to change relation :files of Asset but the :on_replace option of this relation is set to :raise. Yes this was what I was referring to. That means there are existing associa…

Do these updates happen atomically? Or if something goes wrong mid changes you end up with half of the updates?

I just tested it and it wraped the insert in a transaction. if one of subsequent operations fails, it rolls back the previous changes.

Elixir Programming Language Forum

Update nested struct with Ecto

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helicon April 1, 2019, 8:59am 5

yes it really works. Thank u.