Consider:

- a table with an assigned PK (i.e. not auto-increment), let's call this "A"
- Another table ("B") linked to the table listed above but with it's PK set to auto-increment.

Now if you try to save B with cascading switched on, it will break. From the little debugging I've done it looks like:

a) hibernate detects that A needs to be saved first, but puts it into some sort of queue.
b) when it hits B, it short-circuits this save queue and tries to save B immediately so as to obtain a PK reference for B. This fails since A hasn't been yet been saved so it's link is still null.

Can anyone please confirm this before I open a Jira issue?

Thanks.


Schema used is listed below (MySQL):
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CREATE DATABASE `jira` /*!40100 DEFAULT CHARACTER SET latin1 */;

DROP TABLE IF EXISTS `jira`.`parent`;
CREATE TABLE `jira`.`parent` (
`parent_id` int(10) unsigned NOT NULL,
PRIMARY KEY (`parent_id`)
) ENGINE=InnoDB DEFAULT CHARSET=latin1;

DROP TABLE IF EXISTS `jira`.`child`;
CREATE TABLE `jira`.`child` (
`child_id` int(10) unsigned NOT NULL auto_increment,
`parent_id` int(10) unsigned NOT NULL,
PRIMARY KEY (`child_id`),
KEY `FK_child_1` (`parent_id`),
CONSTRAINT `FK_child_1` FOREIGN KEY (`parent_id`) REFERENCES `parent` (`parent_id`)
) ENGINE=InnoDB DEFAULT CHARSET=latin1;

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P.S. Tested this with versions 3.2.5, 3.2.6 and 3.3