[dunhill]

I have different separate libraries and I was thinking about generating an id to group them
Although Calibre assigns one id per book record, I would like to be able to give my id an 8-digit format and for the first to be, for example, 00000001 and from this the rest are listed successively automatically.
At the beginning I said I create a custom column that depends on the calibre id record and I give it the 8-digit format.
And then I realized that this id, as in any database, is not correlative, due to possible deleted books.
And that the second library should have an id with this format 100000000 being autonumeric or correlative
That's why my question is, how could something similar be done?
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