Possibly-missing capabilities: count, missing and columns

[QuintinWillison]

Something that came up (thanks to Claude) during my cross-SDK analysis whilst planning for the Go SDK's PostgREST write operations...

🤖:

there is no capability id for a count preference on mutations, none for missing=default (the JS defaultToNull option) and none for the columns query parameter

Might be something, could be nothing, but I wanted to to capture somewhere for investigation later.

[dhruvxvaishnav]

Hi, I'd like to work on this. The existing insert and upsert specs already describe these behaviors, and I found matching public SDK behavior for mutation counts and default handling. I'll add independently trackable, SDK-agnostic capabilities for mutation counts, using database defaults for omitted values, and bulk writes with differing row fields, rather than treating the raw columns query parameter itself as the public capability.

[dhruvxvaishnav]

Hi @QuintinWillison, I have the implementation ready on this branch. It adds the three SDK-agnostic mutation capabilities and focused specs discussed above. The full test suite passes on Linux (214 tests), along with type-checking and both offline and online matrix validation. I tried to open a PR, but GitHub reports that this repository currently limits PR creation to collaborators. Could you let me know the preferred way to submit this change?

[QuintinWillison]

Thanks, @dhruvxvaishnav - I appreciate your enthusiasm to continue being involved, but as you've seen we've recently decided to stop taking external PRs into this repository, due to volume of low quality ones inbound (often agentically generated). I'm discussing with the rest of the team and will get back to you. Bear with us. Thanks!

[dhruvxvaishnav]

No worries @QuintinWillison, I understand that having high volume of PRs with lower quality would make your work more hard and tedious rather than helping you. Nevertheless, if you and team decide to accept external PRs, I will keep this branch and will merge at that time. Once again, thank you for letting me know.

[QuintinWillison]

@dhruvxvaishnav Thanks again for the contribution... I've sponsored your PR - my review here: #194 (review)

Related: #193