Hibernate - Fetching associations
刚又去看了看Hibernate in action，fetching associations
In HQL, you can specify that an association should be eagerly fetched by an
outer join using the fetch keyword in the from clause:
from Item item left join fetch item.bids where item.description like '%gc%'
This query returns all items with a description that contains the string gc, and all
their bids, in a single select. When executed, it returns a list of Item instances, with
their bids collections fully initialized. We call this a from clause fetch join. The purpose
of a fetch join is performance optimization: We use this syntax only because
we want eager initialization of the bids collections in a single SQL select
■ HQL always ignores the mapping document eager fetch (outer join) setting. If
you’ve mapped some associations to be fetched by outer join (by setting
outer-join="true" on the association mapping), any HQL query will ignore
this preference. You must use an explicit fetch join if you want eager fetching
in HQL.
原来在映射文件里设置了outer-join="ture"，如果在HQL不用fetch的话，一样不会initialized.
希望大家也注意一下：）
BTW:join fetch很好用，前面不知道，每次在jsp因为没有initialized关闭了session而头痛：）