hibernate hql join hashset问题

发布于 2024-12-03 15:51:10 字数 453 浏览 0 评论 0原文

我有三个表

users、survey、surveyreponses

我使用 hibernettool 生成

survey 对象中的对象/映射/xml 等，有一组 surveyresponses

private Set Surveyresponses = 新的哈希集（0）； <-- 这是调查类中生成的代码

我正在运行查询，

select u.id, s from users u, survey s
where u.id = s.id

但我的调查响应“集”为空。如何将所有这些调查回复添加到调查集中？假设我从 Surveyresponses 中引用了调查 id，

这对 Hibernate 来说有点陌生 =) 谢谢

原文

I have three tables

users, survey, surveyreponses

I used hibernettool to generate the objects/mapping/xml etc

in the survey object there is a "set" of surveyresponses

private Set surveyresponses= new HashSet(0); <-- this is generated code inside survey class

I am running the query

select u.id, s from users u, survey s
where u.id = s.id

but my surveyresponses "set" is empty.
How do I add all those surveyresponses into the set in survey?
assuming I have the reference to survey id from surveyresponses

kinda new to hibernate =)
thanks

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旧人九事 2024-12-10 15:51:10

那是因为当您执行 HQL 时，您将获得一个列表，其中包含查询中的对象，但它不会填充对象中的属性。您需要做的是在调查配置中指定一组调查响应，如下所示：

<set name="surveyresponses" inverse="true" lazy="true"  cascade="all-delete-orphan">                    
    <key>
        <column name="id" precision="10" scale="0" not-null="true" />
    </key>
    <one-to-many class="surveyresponse" />
</set>

现在，每当加载调查时，Hibernate 就会填充您的调查集。

Thats because when you are doing HQL you will get a List that has the objects from your query in it, but it won't populate properties in your objects. What you need to do is specify the set of survey responses in your survey's configuration like so:.

<set name="surveyresponses" inverse="true" lazy="true"  cascade="all-delete-orphan">                    
    <key>
        <column name="id" precision="10" scale="0" not-null="true" />
    </key>
    <one-to-many class="surveyresponse" />
</set>

Now whenever the survey is loaded Hibernate will populate your set.

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