msmithstubbs
Assume an Author schema:
schema "authors" do
field :name, :string
has_many :posts, Post
end
def changeset(struct, attrs) do
struct
|> cast(attrs, [:name])
end
I can perform an update:
author |> Author.changeset(%{name: "Jo"}) |> Blog.Repo.update!()
but an upsert fails:
author |> Author.changeset(%{name: "Jo"}) |> Blog.Repo.insert!(on_conflict: {:replace_all_except, [:id]})
** (RuntimeError) attempting to cast or change association `posts` from `Author` that was not loaded. Please preload your associations before manipulating them through changesets
Is it possible to perform an upsert without loading the associations?
Or is this by design?
Where Next?
Trending in Questions
Other Trending Topics
Latest on Elixir Forum
Sponsor Spotlight
Supporting innovation across the BEAM ecosystem.
Categories:
Sub Categories:
Forums
Popular Tags
- #ecto
- #liveview
- #troubleshooting
- #learning-elixir
- #library
- #deployment
- #erlang
- #testing
- #genserver
- #mix
- #absinthe
- #remote-other
- #otp
- #plug
- #how-to-question
- #macros
- #postgres
- #elixirconf
- #channels
- #exunit
- #discussion
- #code-sync
- #podcasts
- #javascript
- #onsite
- #dialyzer
- #docker
- #authentication
- #ai
- #umbrella
- #full-time-contract
- #podcasts-by-brainlid
- #blog-post
- #ecto-query
- #elixirconf-us
- #elixir-ls
- #phoenix_html
- #iex
- #graphql
- #genstage
- #websockets
- #supervisor
- #advent-of-code
- #distillery
- #processes
- #elixirconf-eu
- #api
- #forms
- #security
- #hex
Our Sponsors
Build Elixir applications with speed and confidence.
Supporting innovation across the BEAM ecosystem.
We build reliable cloud platforms for business-critical systems.
Catch errors, track performance, monitor hosts and more.
Elixir, Erlang & BEAM conferences from Code Sync - join us in 2026!
Practical resources that improve the lives of professional developers.
Bringing learning, work and compliance together since 1987.
Producing high quality Elixir screencasts since 2017.
The team behind Membrane, Popcorn, LiveDebugger. Available for hire.
Courses that'll move you from confusion to "Aha, now I get it!"
Showing Posts 1 to 4- Show Best Posts
- Show All (oldest first)
- Show All (newest first)
frfroes
Have you taken a look at
Repo.insert_all/3? They have a full section on upsert, maybe that helps.Something like
LostKobrakai
Maybe
Repo.insert_or_updateis what you’re looking for. A changeset is already aware if you loadedauthorfrom the db or not.al2o3cr
The code that implements
replace_all_exceptstarts from the schema’s list of fields:https://github.com/elixir-ecto/ecto/blob/479484c2dfe637cecb623293a712a2e77632b846/lib/ecto/repo/schema.ex#L721-L723
And that’s a list of built from all the
fieldcalls inside theschemablock - associations aren’t in there.Can you post the stacktrace of the error and/or the full source of
Author.changeset/2?msmithstubbs
Thanks for all the feedback. Along with a discussion on the Elxir discord I’ve improved my understanding of how upsert works.
What I should be doing is this:
If the struct metadata state is
builtthen it works fine. If it’sloadedthen the associations are expected.I want to avoid loading it first, and just insert or update an existing record, so using a built struct is the best approach.
If I had the struct already loaded I can use
insert_or_update