Re: Re: Getting last record ID created from DB

markw@mohawksoft.com wrote:

markw@mohawksoft.com wrote:

On Sat, 2007-03-17 at 12:19 -0400, Mark wrote:

There in lies the biggest problem with LAMP, and that's MySQL. The architecture of your methodology *only* works with MySQL, and not more capable databases like Oracle, DB2, or even PostgreSQL.

I too thought the same thing, but was corrected when I starting working on a redesign for the billing system for the company that I am working for. They use PostgreSQL and we do have a auto incremented unique id field. It isn't call AUTO_INCREMENT, but rather a sequence value. It is a value that is controlled by the default value entry. It then runs this: nextval('customers_customer_id_seq'::regclass) and uses this as the value of the id field for the newly inserted row.

Yea, I've been using PG for over 10 years now. Sequences are awesome, but there have an "auto number" column type as well. It simply creates a sequence but it's there. I guess maybe most databases support the notion of "auto number" in some form. I haven't used MSSQL recently, but I think their solution is a GUID.

Then instead of running a command like SELECT LAST_INSERT_ID(); you have to do some other stuff like this: $SQL = "SELECT currval('{$table}_{$column}_seq');";

Again, this is absolutely wrong unless it is wrapped in a transaction. You will need a "begin" and a "commit" in an MVCC type system. If you don't wrap it in a transaction you don't know who got the last "nextval" of the sequence.

Check the documentation - currval returns the last one *for that session* - it does not return the last global change. http://www.postgresql.org/docs/current/static/functions-sequence.html It is perfectly safe to use this. -- Postgresql & php tutorials http://www.designmagick.com/