[RESOLVED] Mysql_insert_id

[netfrugal]

This is a curiosity of mine, so my question may not even make sense to some. However, I must ask so I know for sure.

This is the definition of mysql_insert_id:
mysql_insert_id — Get the ID generated from the previous INSERT operation

This makes sense, and is pretty handy to use. But I was thinking, what happens if 2 separate customers submit data to the DB at the same exact time, or if execution timing is off for one customer?

Does mysql_insert_id() only get the ID generated from the INSERT operation from that browser?

I suppose I'm trying to understand if there is a con to using this function.

Any thoughts?

[laserlight]

Well, I thought I read somewhere that mysql_insert_id() will return the id generated for the connection provided (or the current connection, if none is specified), but now reading this makes me think otherwise:

Note: Because mysql_insert_id() acts on the last performed query, be sure to call mysql_insert_id() immediately after the query that generates the value.

[netfrugal]

I agree, it makes you wonder!

Even if I mysql_insert_id() immediately after the query, is there a possibility that a collision may occur?

[Piranha]

From the MySQL manual:

For LAST_INSERT_ID(), the most recently generated ID is maintained in the server on a per-connection basis. It is not changed by another client. It is not even changed if you update another AUTO_INCREMENT column with a non-magic value (that is, a value that is not NULL and not 0). Using LAST_INSERT_ID() and AUTO_INCREMENT columns simultaneously from multiple clients is perfectly valid. Each client will receive the last inserted ID for the last statement that client executed.

Edit: This quote is from the C section of the MySQL manual. But I doubt that it is different for PHP.

[netfrugal]

Thanks for that information, very helpful to know that it is connection dependant!