[bug#32121] [PATCH 3/5] database: Add support for database upgrades.

[ludo@gnu.org (Ludovic Courtès)]

Hello,

Clément Lassieur <clement@lassieur.org> skribis:

> Clément Lassieur <clement@lassieur.org> writes:
>
>> +(define (db-get-version db)
>> +  (if (pair? (sqlite-exec db "SELECT name FROM sqlite_master WHERE \
>> +type='table' AND name='SchemaVersion';"))
>> +      (vector-ref
>> +       (car (sqlite-exec db "SELECT MAX(version) FROM SchemaVersion;")) 0)
>> +      0))
>> +
>> +(define (db-set-version db version)
>> +  (sqlite-exec db "INSERT INTO SchemaVersion (version) VALUES (" version
>> +               ");"))
>
> Actually, there is:
>
> PRAGMA schema.user_version;
> PRAGMA schema.user_version = integer ;
>
> The user_version pragma will to get or set the value of the user-version
> integer at offset 60 in the database header. The user-version is an
> integer that is available to applications to use however they
> want. SQLite makes no use of the user-version itself.
>
> Better use them than creating an ad-hoc table I guess, WDYT?

Sounds good, yes.

Thanks,
Ludo’.