如何在Doctrine 2.0中编写这个SQL查询(并获取结果)?如何在Doctrine 2.0中编写UNION
(SELECT 'group' AS type, CONCAT(u.firstname, " ", u.surname) as fullname, g.name AS subject, user_id, who_id, group_id AS subject_id, created FROM group_notification JOIN users u ON(who_id = u.id) JOIN groups g ON(group_id = g.id))
UNION
(SELECT 'event' AS type, CONCAT(u.firstname, " ", u.surname) as fullname, e.name AS subject, user_id, who_id, event_id AS subject_id, created FROM event_notification JOIN users u ON(who_id = u.id) JOIN events e ON(event_id = e.id))
ORDER BY created
该解决方案的解释如何? – ihsan 2014-12-25 01:04:42
@ihsan你可以从基类库('Notification')中选择,并且你可以得到子类型的所有对象('NotificationGroup','NotificationEvent',甚至只是'Notification',如果你还没有声明它是抽象的)。如果你只需要某些类型,那么你可以在WHERE中使用'INSTANCE OF'运算符。 – 2016-02-04 12:44:43