foreign key data corruption?

[Borre Mosch]

Hi,

I have a database in which 2 tables (using the innoDB storage engine) exist:

CREATE TABLE IF NOT EXISTS `table1` (
`table2_id` int(11) NOT NULL,
PRIMARY KEY (`table2_id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;

CREATE TABLE IF NOT EXISTS `table2` (
`id` int(11) NOT NULL,
`name` varchar(64) NOT NULL,
PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;

There is also a foreign key constraint between the 2 tables:

ALTER TABLE `table1`
ADD CONSTRAINT `table1_ibfk_1` FOREIGN KEY (`table2_id`) REFERENCES `table2` (`id`) ON DELETE CASCADE ON UPDATE CASCADE;

Now there is a row in table1 with table2_id '15'. This id, however, does not exist in table2. When I delete the row and try to re-insert it, this obviously fails as it should. My question is: is this, under certain circumstances, expected behaviour, or is some serious data corruption involved?

Thanks in advance,

Borre