reight
How do I destroy all records?
Hello all,
Is there an idiomatic way to destroy all records in the table with Ash Framework, similar to read_all()?
Or maybe some escape hatch to Ecto?
I tried to do it with manual action, but it requires changeset.
The only way I could think of is to do it with generic action, something like
action :destroy_all, :string do
argument :dummy, :string, allow_nil?: true
run(fn _input, _context ->
read_all!()
|> Enum.map(&destroy!(&1))
{:ok, []}
end)
end
But that’s suboptimal, to say the least.
EDIT: clarification that the question is Ash related
Marked As Solved
reight
Thank you all for your help!
So just to close the case, I ended up using following generic action:
actions do
defaults [:create, :read, :update, :destroy]
action :destroy_all, :term do
run(fn _, _ ->
case __MODULE__
|> MyApp.Repo.to_ecto()
|> MyApp.Repo.delete_all() do
{n, result} when is_integer(n) -> {:ok, result}
error -> {:error, error}
end
end)
end
end
And that gives me MyApp.Api.Resource.destroy_all()
Also Liked
sbuttgereit
I would agree that TRUNCATE would be the first choice if all conditions allow… and in many basic scenarios you’ll be fine; but one needs to use TRUNCATE with some care in more complex scenarios. (Assuming PostgreSQL)
-
There are special considerations if the table is used in other table foreign key references.
-
If you have
ON DELETEtriggers, they will not fire. -
TRUNCATEis not fully MVCC safe in relation to certain concurrent transactions.
and there are one or two other more subtle issues as well (PostgreSQL: Documentation: 16: TRUNCATE).
Because of the special nature of TRUNCATE and the efficiency it tries to bring to mass delete operations, there can be similar issues in other vendor’s databases as well. For example, in PostgreSQL, while fully not MVCC safe, you can roll back a TRUNCATE operation, but in Oracle you cannot.
So I would advise anyone needing to delete all the data in a table to TRUNCATE if they can, but it’s one of those commands that you really need to understand and use with care.
netto
If anyone else comes across this like I did, there is now a bulk_destroy function.
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