Thread

Re: Key joins

Laurenz Albe <laurenz.albe@cybertec.at> — 2026-05-29T12:51:23Z

On Thu, 2026-05-28 at 20:47 +0200, Joel Jacobson wrote:
> This patch implements a new SQL language feature, that we intent to
> submit as a Change Proposal to the WG 3 SQL committee for the next
> meeting in Stockholm in June.  We would greatly appreciate any feedback
> from the community.

Your presentation at the pgconf.dev really convinced me that this is
a useful feature.

I had only one consideration:

> FROM orders o
> LEFT JOIN order_items oi FOR KEY (order_id) -> o (id)

In the spirit of looking more like SQL, how about replacing the
arrows with FROM and TO?

Either

  a JOIN b FOR KEY (col1) TO (col2)

or, slightly more verbose and natural language-like:

  a JOIN b FOR KEY FROM (col1) TO (col2)

And if the arrow points the other way,

  a JOIN b FOR KEY (col1) FROM (col2)

or

  a JOIN b FOR KEY TO (col1) FROM (col2)

Yours,
Laurenz Albe