🚀 go-pugleaf

Hi Umberto,
here there is the same problem, I'll have to lock the table before using the
query you wrote, because if there are 2 readings before the row has been
inserted, 2 new records will have the same id, and then one will be rejected
by the index.
Another thing, I don't know how to translate 'fattura' in english, but you
are italian (aren't you? :-), and you surely know what I mean.
This fattura must have consequent numbers and consequent dates, so I can't
have a fattura with previous number but later date, and this should be the
case if a previous number is picked with a later date.

Ciao
    Formentz

"Umberto Uderzo" <umberto@uderzo.it> ha scritto nel messaggio
news:3b44f7c5_2@dnews...
> Hello Francesco,
>
> Ok, if your need is to obtain contiguous ids your way is sure right.
> But what if the table is used by many users and the row creation process
> involves much time?
> You gain a lot of waiting locks...
> If you can have temporary holes in your id sequence you can use the
> following query:
>
> SELECT MIN(t1.id)+1
> FROM <table_name> t1
> WHERE NOT EXISTS
>             SELECT t2.id
>             FROM <table_name> t2
>             WHERE t2.id = t1.id + 1
>
> So if there are holes in your id sequence, the next query will fill the
> first hole of the sequence.
>
> Ciao... Umberto Uderzo
>