Hibernate的Criteria API还不支持嵌套关系吗

发布于 2024-08-02 03:14:05 字数 971 浏览 4 评论 0原文

我想使用 Hibernate 的 Criteria API 来实现每个人所说的最可能的用例,即应用复杂的搜索条件。 问题是,我想要查询的表并不完全由原始值组成,而是部分由其他对象组成,并且我需要查询这些对象的 id。

我发现 这篇文章表明这是不可能的。 这是我尝试的方法,但没有成功,Hibernate 还有其他方面,我知道在字符串文字中支持这种点符号来指示对象嵌套。

   if (!lookupBean.getCompanyInput().equals("")) {
       criteria.add(Restrictions.like("company.company", lookupBean.getCompanyInput() + "%"));
   }

编辑:

这是我正确分解的代码,用于完成我上面尝试的操作,使用下面第一个答案中的建议; 请注意,我什至使用额外的 createCriteria 调用来对另一个关联对象/表中的属性进行排序:

if (!lookupBean.getCompanyValue().equals("")) {
    criteria.createCriteria("company").add(
           Restrictions.like("company", lookupBean.getCompanyValue() + "%"));
}

List<TrailerDetail> tdList = 
        criteria.createCriteria("location").addOrder(Order.asc("location")).list();

I'd like to use Hibernate's Criteria API for precisely what everybody says is probably its most likely use case, applying complex search criteria. Problem is, the table that I want to query against is not composed entirely of primitive values, but partially from other objects, and I need to query against those object's id's.

I found this article from 2 years ago that suggests it's not possible. Here's how I tried it to no avail, there are other aspect of Hibernate where I know of where this sort of dot notation is supported within string literals to indicate object nesting.

   if (!lookupBean.getCompanyInput().equals("")) {
       criteria.add(Restrictions.like("company.company", lookupBean.getCompanyInput() + "%"));
   }

EDIT:

Here's my correctly factored code for accomplishing what I was trying above, using the suggestion from the first answer below; note that I am even using an additional createCriteria call to order on an attribute in yet another associated object/table:

if (!lookupBean.getCompanyValue().equals("")) {
    criteria.createCriteria("company").add(
           Restrictions.like("company", lookupBean.getCompanyValue() + "%"));
}

List<TrailerDetail> tdList = 
        criteria.createCriteria("location").addOrder(Order.asc("location")).list();

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感受沵的脚步 2024-08-09 03:14:05

不完全确定我遵循您的示例,但肯定可以在关联实体上指定过滤条件,只需嵌套 Criteria 对象来形成树即可。 例如,如果我有一个名为 Order 的实体,与 User 实体具有多对一关系,我可以通过查询查找名为 Fred 的用户的所有订单像这样:

List<Order> orders = session.createCriteria(Order.class)
    .createCriteria("user")
        .add(eq("name", "fred"))
    .list();

如果您正在谈论一个与其自身有关系的实体,那么它也应该有效。 如果需要过滤关联对象的 ID,您还可以将“name”替换为“id”。

Not entirely sure I follow your example, but it's certainly possible to specify filter conditions on an associated entity, simply by nesting Criteria objects to form a tree. For example, if I have an entity called Order with a many-to-one relationship to a User entity, I can find all orders for a user named Fred with a query like this:

List<Order> orders = session.createCriteria(Order.class)
    .createCriteria("user")
        .add(eq("name", "fred"))
    .list();

If you're talking about an entity that has a relationship to itself, that should work as well. You can also replace "name" with "id" if you need to filter on the ID of an associated object.

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