feat: Add support for auto-incremented SERIAL columns

[ml31415]

Fixes #289

[dhirschfeld]

I just ran into this again 😬
It would be great to get this in here to work around the limitation in duckdb

[ml31415]

Hi @Mause ! Would you mind reviewing this PR? I guess it's the best workaround for the SERIAL issue currently available, until there is native support for it in duckdb.

[jobh]

👍

It would be nice to include SMALLSERIAL/SMALLINT as well.

[dhirschfeld]

It would be great if a similar trick could be used to support GENERATED ALWAYS AS IDENTITY which is the standardised form (which postgres also supports).

• https://peter.eisentraut.org/blog/2023/10/31/sql-identity-columns
• https://www.danieleteti.it/post/postgresql-identities-vs-serials/

Maybe that's tricky enough to be best left for a follow-up PR though...

[ml31415]

It would be great if a similar trick could be used to support GENERATED ALWAYS AS IDENTITY which is the standardised form (which postgres also supports).

I guess this would better be handled by duckdb itself, as you mentioned there already: duckdb/duckdb#1768