jpql按子查询顺序产生意外的AST节点异常 [英] jpql order by subquery produces unexpected AST node exception

问题描述

我将一个工作（postgre）sql查询翻译成jpql，但是hibernate抛出一个

I translated a working (postgre)sql query to jpql, but hibernate throws a

org.hibernate.hql.ast.QuerySyntaxException ：
意外的AST节点
异常

org.hibernate.hql.ast.QuerySyntaxException: unexpected AST node exception

这些是我的核心模型类：

These are my core model classes:

@Entity
public class Piece {
    @Id
    @GeneratedValue
    public Long id;

    @ManyToOne
    public AUser user;
    public long index;
...
}

@Entity
public class Vote {
    @Id
    @GeneratedValue
    public Long id;

    @ManyToOne
    public AUser receiver;
...
}

@Entity
public class AUser {
    @Id
    @GeneratedValue
    public Long id;

    @OneToMany(mappedBy="receiver", cascade=CascadeType.ALL)
    public List<Vote> receivedVotes;
...
}

这是我的jpql查询：

Here is my jpql query:

String query = "select p from Piece p order by (select count(v.receiver) from Vote v where v.receiver.id=p.user.id) desc, p.index";

任何人都可以解释异常，为什么会发生，以及如何更改查询以避免它。感谢！

Can anyone explain the exception, why it happens and how to change the query to avoid it. Thanks!

推荐答案

JPQL不支持顺序中的子查询。如果我正确理解您的查询，您可以尝试如下所示：

JPQL doesn't support subqueries in order by. If I correctly understand your query, you can try something like this:

select p 
from Piece p left join p.user.receivedVotes rv
group by p
order by count(rv) desc, p.index

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