[12.x] Adds findOnce and findOrFailOnce methods for Eloquent

[sethsandaru]

Hi team,

It is quite a normal use case that we use find or findOrFail multiple times within the same request - which results in multiple queries to the database.

The usual workaround is to cache the result via static properties or a Context, but that adds another unnecessary layer in userland.

So this PR introduces the findOnce and findOrFailOnce methods. Both are nice-to-have and provide a small performance improvement per request.

Personal taste: I did add these methods using macro, but I don't really like macro. Extending Builder is fine, but then I’d have to create a new BaseModel to use that extended Builder class, etc.

(If this gets accepted, I’ll open a PR to update the docs.)

[shaedrich]

Shouldn't find() always return TModel? For \Illuminate\Database\Eloquent\Collection<int, TModel>, we have get()

[sethsandaru]

We can pass an array/collection of IDs to fetch multiple records, though (it’s also mentioned in the original phpDoc of find and findOrFail)

But same here - I also always use find for fetching a single record and get() for a list 😄

[shaedrich]

But what was the decision to not have a getOnce()?

[sethsandaru]

That could be a good follow-up candidate after this one - but first, we probably want to see whether the Laravel team is open to the whole *Once idea.

[taylorotwell]

Thanks for your pull request to Laravel!

Unfortunately, I'm going to delay merging this code for now. To preserve our ability to adequately maintain the framework, we need to be very careful regarding the amount of code we include.

If applicable, please consider releasing your code as a package so that the community can still take advantage of your contributions!