How to do ensureQueryData with Tanstack DB?

[coryhouse]

Scenario: I'd like to prefetch data without using a join. A join prefetches, but it also blocks rendering until complete. Tanstack Query's ensureQueryData quietly fetches in the background, and doesn't block rendering. I tried using it with Tanstack DB, but it doesn't appear to work.

Related post: https://x.com/housecor/status/1962621474478444662

[KyleAMathews]

Collections have a .preload() method on them that returns a promise that resolves when the data is loaded.

Something else that occurs to me that we haven't done is that a new query collection could check the keys for data and use that for the initial load? I'm not entirely sure if that makes sense.

[KyleAMathews]

It also seems like left/right joins could also have a setting which doesn't block on loading the non-required collection — which seems like a good fit for the use case in your tweets.

[KyleAMathews]

cc @samwillis

[coryhouse]

It also seems like left/right joins could also have a setting which doesn't block on loading the non-required collection — which seems like a good fit for the use case in your tweets.

Thanks! The preload works great, and yes some way to specify what part of the join should block would help, though the downside would be there's not an equivalent in SQL, which starts to muddy the abstraction.

[KyleAMathews]

@samwillis shipped this #658 — it means that queries now eagerly run whenever any of their sources load data — which means you can await one of the sides of the join loading and not the other.

[coryhouse]

Excellent, thanks for the update @KyleAMathews! So should this issue be closed?

[KyleAMathews]

Yes