[eluser]TheFuzzy0ne[/eluser]
There's no such thing as a "permanent" connection. Persistent, yes, but with a persistent connection db_insert_id() will
still return the ID of the last row
inserted via that connection ID. If you insert 10 rows, you will only get the ID of the last row that was inserted
by that connection.
If another process was inserting rows at the same time, db_insert_id() would return the ID of the last row that was inserted by
that connection.
Database connections are isolated from one another.
Remember, db_insert_id() only returns the ID of the last row inserted
with that connection, it is unaware of any other database connections. The purpose of db_insert_id() is to get the ID of a row that's just been inserted. It would be useless if, on a busy site, it started handing out insert IDs for other rows. I use it every day, and millions of other developers do too, and they don't have any problems with it.
