How to get struct from map - elixir?

[silverdr]

I encountered a similar problem today. Wanted a minimal set of fields to process frequently so created a smaller struct, with only a subset of key/value pairs of the full one. Then I fetch data from the DB in a manner very similar to the one described here:

Has_many through load selected associated columns

select can do it in “one go” as well. user |> Ecto.assoc(:chatrooms) |> select([cr], map(cr, [:id, :name])) |> Repo.all()

IOW I am getting a Map (well, list of maps in that particular example there) with only the key/value pairs I am interested in and pass it to struct!2

struct!(%MyMinimalStruct{}, my_map_from_db_query)

Seems almost suspiciously trivial… any gotchas?

Alternative could be to create another “model” with limited Ecto.Schema defnition. Might check that route too