MySQL: LAST_INSERT_ID() returns 0

Question

I've got this test table:

CREATE TABLE IF NOT EXISTS `test` (     `id` INT(10) AUTO_INCREMENT,     PRIMARY KEY (`id`) ) ENGINE=InnoDB AUTO_INCREMENT=4; 

inserting using either of these three

INSERT INTO `test` (`id`) VALUES (NULL); INSERT INTO `test` (`id`) VALUES (0); INSERT INTO `test` () VALUES (); 

and issuing

SELECT LAST_INSERT_ID(); 

but the query always results in 0.

PHP's mysql_insert_id and PDO::lastInsertId() yield no result either.

I've been toying with this whole day and can't get it to work. Ideas?

Answer 1

The problem seemed to be in MySQL's phpmyadmin config file PersistentConnections set to FALSE which resulted in a new CONNECTION_ID every time a query was issued - therefore rendering SELECT LAST_INSERT_ID() ineffective.

more info in the subsequent topic Every query creates a new CONNECTION_ID()

Also thanks dnagirl for help

Answer 2

Just my 50 cents for this issue, I simply noticed that you won't get a LAST_INSERT_ID greater than 0 if your table has no AUTO_INCREMENT set to an index.

I wasted about half hour on this. Turns out I keep getting a LAST_INSERT_ID() of 0, which for this table is actually ok.