OK, I think that did it.
Here is the MySQL query in its full working glory;
SELECT DISTINCT
`test_event`.`name`,
`test_event`.`id`
FROM
`test_event`
Left Join `test_eventbook` ON `test_event`.`id` = `test_eventbook`.`eventId`
WHERE NOT
(
(`test_eventbook`.`bookStart` <= '2008-05-03...