>> With regard to mysql's mysql_insert_id function is it possible that the
query can return the insert id from another insert performed by a
another user of the database which occured after the initial insert by
the first user but b4 the insert_id part can be queried.
You won't have any problems if you're running it immediately after the
query.
In the database world, there is no "immediately after". It's always
possible for someone else to get in a query between any two of
yours. It's up to locking (implicit or explicit) or transactions
to prevent bad effects on the data from this by delaying execution
of one until another finishes.
mysql_insert_id() returns the last insert id ON THIS CONNECTION.
So, as long as you keep the connection open (which probably won't
be beyond the processing of the PHP page: with persistent connections,
you are NOT guaranteed to get the same connection next time), you
can wait as long as you want to call mysql_insert_id().
Gordon L. Burditt