1stSolo
Does lock_version need to be cast() into ChangeSet, or doing
changeset
|> optimistic_lock(:lock_version)
is enough?
I mean, AFAIK every attempt to update an object should have lock_version in the attributes map, so how does Ecto know what value to use for lock_version if we don’t put it into changeset by casting it?..
But when I look at examples online and in documentation all I see is ChangeSet.optimistic_lock/3 being called.
Trending in Questions
I’m working on a project that simulates the bumbl example in the programming phoenix book. It acts almost like an email client. We have a...
New
Hello,
I know there is an approach for handling lists that allows for optimized traversal, but I can’t recall the specific method (somet...
New
Documentation
While reading the Scoped Routes section, I noticed that the documentation currently refers to a problem without explainin...
New
I’m seeing that a list inside a Kino.DataTable will be interpreted as a charlist, even if the Kino.configure() is set to charlists: :as_l...
New
So my question is quite simple and i have found no conclusive answer on forum, google or AI.
Should we use :erlang.float for Integer to ...
New
I recently noticed that Elixir’s Logger defaults its primary log level to :debug when no :logger, :level application configuration is pre...
New
Hi, I’ve just set up an application with ash_authentication. There is only magic link strategy for now, so there is no confirmation add o...
New
Other Trending Topics
Hey, I’m Jesse and I’m the main contributor behind Dexter, a full-featured, lightning-fast Elixir LSP optimized for large codebases. It s...
New
I am happy to introduce the very α version of the new programming language compiled to BEAM.
Welcome Cure.
It has literally three kille...
New
Hi there! We created Gust: A task orchestrator inspired by Airflow.
For those who have never heard about Aiflow, it’s a Python-based wor...
New
Hi everyone!
The first release candidate for the Expert language server project is now available!
We’ve published a press release detai...
New
Beam Bots (or just BB for short) is a framework for building fault-tolerant robotics applications in Elixir using familiar OTP patterns. ...
New
Xamal is a deployment tool for Elixir apps that deploys native releases to bare metal servers over SSH. It’s a port of GitHub - basecamp/...
New
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
- #umbrella
- #full-time-contract
- #podcasts-by-brainlid
- #ecto-query
- #elixirconf-us
- #ai
- #blog-post
- #elixir-ls
- #phoenix_html
- #iex
- #graphql
- #genstage
- #websockets
- #supervisor
- #advent-of-code
- #distillery
- #processes
- #api
- #forms
- #metaprogramming
- #hex
- #security











First Post!- Show Best Posts
- Show All (oldest first)
- Show All (newest first)
woylie
It just gets the field from the changeset source:
https://github.com/elixir-ecto/ecto/blob/4a143348ab89e0174a1a5082fd47d868ebd9689b/lib/ecto/changeset.ex#L3418
You don’t need to cast just to access the source data. And you don’t want to cast the lock version, because you don’t want the value to be set from the parameters.
Most Liked
1stSolo
In my case I have a absinthe client that pulls the object from the backend via graphql, and edits some fields on the object. The save operation takes
idof the object, the changed field, e.g.description, andlockVersionfrom the last time the data was pulled. Multiple users can edit the same object, hence optimistic locking to prevent overwriting someone else’s changes.So
lockVersionactually comes as part of parameters/arguments along with new value fordescription.Therefore I thought the right way to do it is to
which should result in Ecto preparing a SQL statement such as
UPDATE Object SET description=?, lock_version=? WHERE id=? AND lock_version=?, and bindingparams.data.descriptioninto 1st arg, incrementedlock_versioninto second arg,params.idinto 3rd arg andlockVersionfrom the client side into the last arg. Then if updated record count returned by the database driver is 1 then update succeeded and if it’s 0 then Ecto would raiseStaleStateError.So I actually do want to set lockVersion from the params. Is that incorrect?
Last Post!
woylie
Yes, in your case, you’d want to cast the lock version indeed.