HQL如何加入三个表 [英] HQL how to join three table

问题描述

我有这个课程：

 @Entity
 public class Category {
    private Long Id;
    private String name;
    private String description;
    private List<Product> products;
}

@Entity
public class Inventory {

    private Long id;
    private Product product;
    private int quantity;
}

@Entity
public class Product {
    private Long productId;
    private String name;
}

我想在类别中获得给定ID的库存。我正在尝试使用此

I want to get the Inventory given the id in the category. i'm trying to use this

return session.createQuery("select i from Inventory i, Category c join c.Products p outer join i.product = p WHERE c.Id=?")
                .setParameter(0, categoryId).list();

我真的很困惑，请帮忙。谢谢。

I'm really confused, please help. Thanks.

推荐答案

好吧没关系，我发现了怎么做

Alright nevermind, I found out how to do it

Select i from Inventory i,Category c INNER JOIN i.product ip INNER JOIN c.products cp where ip = cp and c.id=?

所以我实际上想知道如何将类别与连接相关联，我在多态查询下找到了答案在HQL文档中

So I was actually wondering how to relate the Category to the joins, I found the answer under Polymorphic queries in HQL documentation

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