如何在Hibernate中进行SELECT查询包括子查询COUNT（*） [英] How to make a SELECT query in Hibernate includes Subquery COUNT(*)

问题描述

假设我们有类别 - 商品 一对多关系。我想这样做

Let's say we have a Category - Items one-to-many relation. I would like to do this

SELECT c.*, 
   (SELECT COUNT(*) FROM items i WHERE i.catId=c.id)
    AS itemCount
FROM category c

假设我们有一个Hibernate POJO类别。

And let's say we have a Hibernate POJO "class Category".

我的第一个问题是我真的无法弄清楚从那个查询我得到一个List< Category>对象吧？我怎样才能访问itemCount？因为没有 Category.getItemCount（）

My first question is I really couldn't figure out that from that query I get a List<Category> object right? And how can I access the "itemCount"? Because there's no Category.getItemCount()

其次，如何编写Criteria查询？

And secondly, how can I write the Criteria query?

谢谢

推荐答案

似乎这就是我正在寻找的答案（进入POJO）：

Seems like this is the answer I was looking for (into to POJO):

@Formula(value="(SELECT COUNT(*) FROM Items i WHERE i.id = id)")
@Basic(fetch=FetchType.EAGER)
public Integer getItemCount() {
   return this.taskCount;
}

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