Database features and API stability

Each new release breaks build, so using the library is like sitting on a time ticking bomb. It's fine when you need to parse literally any SQL query, e.g. you have wild mix of SQLite, MySQL, DuckDB and PostgreSQL commands, but it's rarely needed this way.

It would be better if each database-specific field will be feature-gated, as new syntax added doesn't affect previously added features.

Here struct builders mentioned in another issue would be greatly appreciated.

I would like to contribute into builders part.

L’issue non indica file né test, quindi occorre innanzitutto mappare i campi specifici del database esistenti, la configurazione del feature-gating e il lavoro sullo struct-builder citato qui e nell’altra issue. Restringi quindi la proposta a una milestone concreta del builder o del gating, poi definisci test che dimostrino che le funzionalità del database supportate continuano a essere compilabili senza modifiche alla sintassi non correlate.

Scritto dal modello di indicizzazione a partire dal testo della issue.