休眠子查询 [英] Hibernate subquery

问题描述

在使用Hibernate创建子查询时遇到问题.不幸的是Subqueries类几乎完全没有文档，因此我完全不知道如何将以下SQL转换为Hibernate Criteria:

I have a problem in creating subqueries with Hibernate. Unfortunately the Subqueries class is almost entirely undocumented, so I have absolutely no clue how to convert the following SQL into a Hibernate Criteria:

SELECT id
FROM car_parts
WHERE car_id IN ( SELECT id FROM cars WHERE owner_id = 123 )

我希望以下内容能够正常工作":

I was hoping the following would 'just work':

session.createCriteria(CarParts.class).add(eq("car.owner", myCarOwner));

但不幸的是，事实并非如此.因此，看来我实际上必须使用Subqueries类来创建Criteria.但是我无法通过Google找到一个合理的例子，因此我不得不在这里提出要求.

but unfortunately it does not. So it seems I actually have to use the Subqueries class to create the Criteria. But I was unable to find a reasonable example though Google, so that leads me to asking it here.

推荐答案

在添加eq表达式之前，尝试为"car"属性创建别名:

Try to create an alias for the "car" property before adding the eq expression like this:

session.createCriteria(CarParts.class)  
        .createAlias("car", "c")  
        .add(eq("c.owner", myCarOwner));  

这篇关于休眠子查询的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！