Missing method "find_with_linked"

[nitnelave]

Motivation

We have find_with_related and find_also_linked, but there's no find_with_linked.
For instance, I want to get all users who are in a group whose name is "admin" (not primary key). I have a "membership" table for the N-N relation. I would want to write:

User::find().find_also_linked(Group).filter(Group::Column::Name.eq("admin")).all(db).await?;

Then there's also the question of inner join vs left join. I know the answer is probably going to be pointing me to https://www.sea-ql.org/SeaORM/docs/advanced-query/custom-select/, but it's just a seemingly missing part of the API.

[tyt2y3]

May be related to #1203 ?

[nitnelave]

Somewhat related, but I'm looking to get a Vec<(User, Vec<Group>)>.

[nitnelave]

Actually, I was looking at the custom-select page, and even with custom joins and so on, I can't figure out how to get a Vec<(User, Vec<Group>)>: You can't derive FromQueryResult for a struct with Vec inside, and I'm not sure how to aggregate across rows.

[nitnelave]

So, from what I understand, the only way to do it given the current code (if we want to leverage the link) is to use find_also_linked and then post process the results: we'll get a (User, Some(Group)) for each pair of (user, group), plus a (User, None) for users without groups. If we sort by user, they'll be correctly grouped and we can do some stream processing. Not the prettiest but it works. I still feel like this should be done by the framework.

[tyt2y3]

I think this omission is not intentional and this can be added.
@billy1624 I think it should be a matter of refactoring into prepare_select_two_for_linked and constructing a SelectTwoMany?

Edit: it is due to the fact that SelectTwoMany does not use a hash map, and instead only rely on the order of the first entity. So it can't handle multiple joins in the complex case. If we change the implementation, we will be able to cater both. Alternatively, we can maintain two selector implementations.

[tyt2y3]

Closed by #1743