> > Hello,
> > One simple question... AFAIK I can specify value for an autoincrement
> > primary key (int) when inserting a record like this:
> > INSERT INTO `tablename` (`id`, `name`) VALUES (1, 'test')
> > But it doesn't work for id = 0. Why?
> > I would like to use some primary key values for special purpose, e.g. id
> > means root/default record and so on.
> > Is that recommended? Are there any alternative ways?
> Autoincrement starts from 1. That is the way it is, and cannot, I think,
> be changed.
Yes, it starts from 1, but concrete value CAN be changed to 0 manually.
Maybe it is better to ask: "Why can I set autoincrement primary key to 0 but
cannot do this using INSERT statement?"
> I would advise against using autoincrement keys for "special" uses. This
> is muddling two different functions into one. Remeber that primary keys
> must be unique: if, at some time, you need to have more than one of a
> "special" value, you will be in trouble.
Sure, but the idea was to use 0 for root category or "root" access. It seems
to be reasonable at least.
> The function of autoincrement
> keys is to assign unique record identifiers. Do not mix this with other