Java 如何在hibernate中选择具有其他字段的对象的新实例？

假设我有这些Calss：

public class A {
    public Long id;
    public B b;

    public void setId(Long id) {
        this.id = id;
    }
    public Long getId() {
        return id;  
    }

    public void setB(B b) {
        this.b = b;
    }
    public B getB() {
        return b;  
    }
}

public class B {
    public Long id;
    public String code;

    public void setId(Long id) {
        this.id = id;
    }
    public Long getId() {
        return id;  
    }

    public void setCode(String code) {
        this.code = code;
    }
    public Long getCode() {
        return code;  
    }


    public B(Long id) {
        this.id = id;
    }
}

我想执行这个查询：

select new B(a.b.id) as b, a.b.code as bCode
from A a

但是is不起作用。

试试这个

select new B(b1.id) as b, b1.code as bCode
from A a
inner join a.b as b1