如何用hibernate中的其他字段选择对象的新实例？

Question

假设我有这些calsses：

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 

，但不起作用。

Answer 1

试试这个

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