my original syntax : result = Enum.map( from(Repo, where: ^whitelisted_params) |> where([schema], like(schema.nama, ^"#{nama}%")) |> limit(^query_limit) |> Repo.all(), fn elem -> elem |> Map.from_struct() |> Map.delete(:__meta__) end ) i want to add where([schema]…

|> (fn(n) -> tgl != "" |> where([schema], like(schema.tgl, ^tgl)) || "" end).()`` looks to me that you were trying to do something like this |> (fn(query) -> case tgl do "" -> query _ -> where(query, [schema], like(schema.tgl, ^tgl)) end end).()

Yep, this is a pattern I use super often. I keep meaning to find a way to pipeline it better, but I just tend to have long repeated sets of this small ‘mutation’ chunks (copy/pasted from my sources): query = case refine do [pidm: pidm] when is_integer(pidm) -> where(query, [s], …

thank you all for the response, before the answer from @peerreynders and @OvermindDL1 i use cond with multiple Ecto.Query condition :frowning:

I often have code like that: Enum.reduce(opts, base_query, fn {:category, category}, query -> from a in query, where: a.category == ^category {:tag, tag}, query -> from a in query, where: a.tag == ^tag _, query -> query end)

[image] LostKobrakai: I often have code like that: Oh I have a TON of that too! Also a super common pattern, though my bodies in it tend to be many pages large to handle all the various options that it has when I use it so I figured it would make for an annoying example here. ^.^; sque…

Whenever I have a conditional in a pipeline (which happens all the time) I just write a separate private function, so in your pipeline it would look like this: |> maybe_filter_by_tgl(schema, tgl) Then a separate function: defp maybe_filter_by_tgl(query, schema, tgl) do if tgl != "", do: where(…

[image] tme_317: This is exactly the same as the anonymous function technique from @peerreynders response… for some reason I just find it easier to read (personal preference). The issue then is having to carry a rather massive amount of state through, the examples I gave above are trivial com…

[image] tme_317: the anonymous function technique from @peerreynders response Personally I’m solidly in the private function camp - however in this case only a nudge seemed to be asked for - not a possible lecture from the “style police”. I find discontinuities in the pipe chain increase the…

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Conditional in Ecto.query

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acrolink November 5, 2019, 5:43pm 10

Ingenious, thanks for sharing.