fireproofsocks

fireproofsocks

Forgive me if this is obvious, but how does one delete a database record WITHOUT selecting it first? Ecto.Repo — Ecto v3.14.0 has examples, but they are all doing 2 operations: a select, then a delete.

In the interest of optimization, is it possible with Ecto to delete a record with a single operation? Something like the SQL query DELETE FROM my_table WHERE id=123 ?

Is it considered bad form to delete without selecting first?

Thanks for pointers, as always.

Showing Posts 1 to 8

Adzz

Adzz

Ypu can do something like this:

%MyStruct{id: 10} |> MyApp.Repo.delete

That is just build a struct with the id in it then delete

OvermindDL1

OvermindDL1

Can also look at repo.delete_all/2, it accepts a query for doing just that. :slight_smile:

xlphs

xlphs

from(x in DataModel, where: x.id == ^id) |> Repo.delete_all

fireproofsocks

fireproofsocks OP

I tried that, but that generates an error:
** (Ecto.StaleEntryError) attempted to delete a stale struct

Adzz

Adzz

I think that will only do that if the id you gave it doesn’t exist in the db… maybe it was already deleted?

OvermindDL1

OvermindDL1

From the docs:

If the struct has been removed from db prior to call, Ecto.StaleEntryError will be raised.

So yep, looks like you are right. :slight_smile:

fireproofsocks

fireproofsocks OP

Thank you! Just to show a more thorough example:

{rows_deleted, _} = from(x in DataModel, where: x.id == ^id) |>; Repo.delete_all

You might get zero as the number of rows deleted.

Huolong

Huolong

I think you have to do a query to pass existing rows to delete or delete_all,
because they require the Ecto metadata element of the struct to contain the ‘loaded’ flag.
The only alternative would be to completely fake the whole struct,
including all the internal fields and flags.

But I agree with you that there should be a version of delete,
which just takes a primary key value, by analogy with the ‘get’ function.

— All posts loaded —

Where Next? Top

Trending in Questions Top

stjefim
Hello! Suppose you are building workflow (order / task / payment) processing system with the following requirements: Each workflow con...
New
water
I’m aware of 2 such projects, are there others? git: GitHub - team-alembic/realworld: A fullstack Phoenix LiveView application with back...
New
itzmidinesh
Hi all, I’m working on a Phoenix project where I need to make external HTTP requests and I’m trying to choose between Req and HTTPoison....
New
peck
Hi everyone. My team and I have been working on a fairly modest app based around video streaming and chat, but we’ve landed a customer t...
New
leoschweizer
Hi, we run different LLM models across a cluster, with each node loading a configurable subset. Model-specific queues let nodes consume ...
New
csmr
Hi all, I’m new here and would like to hear peoples views on my Elixir/Phoenix based game-engine! :smiley: Mutonex gamedesign was finish...
New
perzanko
Do we have maintainer of absinthe-graphql/dataloader here? We have a PR that we’d like to merge to the library. Relatively small additive...
New

Other Trending Topics Top

dominicletz
Hey there, I haven’t seen a list of useful Elixir specific skills for the popular AI tools yet so I’m starting one here with my first. ...
New
mudasobwa
I fully migrated to my own harness from Anthropic/Gemini and I think it’s time to share it. Welcome DSH, the DeepSeek Harness, fully writ...
New
KristerV
Hey. Is there anyone here who creates agents in their apps? Not talking about using agents, but creating them. I’m finding it pretty diff...
New
jimsynz
Beam Bots (or just BB for short) is a framework for building fault-tolerant robotics applications in Elixir using familiar OTP patterns. ...
New
webofbits
With AI doing more of the implementation work, I’ve been wondering how much coding I should deliberately keep doing myself. My main conc...
#ai
New
OndrejValenta
(I just needed to vent somewhere and LinkedIn is full of hope, or hype, I’m not sure which exactly) AI dream has many faces, but general...
New

We're in Beta

About us Mission Statement

Options

Thread Display Mode




Thread Preview

Skip Thread Previews