ISBN (was: '{"x": 42, "y": null}'::jsonb != '{"x": 42}'::jsonb ... Really?)

On 2022-06-17 17:14:14 -0700, Bryn Llewellyn wrote:
> "isbn" — string
> values must be unique across the entire set of documents (in other words, it
> defines the unique business key); values must have this pattern:
>
>   « ^[0-9]{3}-[0-9]{1}-[0-9]{2}-[0-9]{6}-[0-9]{1}$ »

Completely off-topic, but this regexp doesn't describe ISBNs. In ISBNs
the three middle subfields are all variable length. The first is a
language code (there are more than 10 languages in the world), the
second identifies the publisher (there are more than 100 publishers) and
the third the book. For example, "Mastering PostgreSQL 9.6" has the ISBN
978-1-78355-535-2.

        hp

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