java - 具有持久子类的非持久父类(super class)

Question

当我保留这个子类时会发生什么？当我在数据库中查询 Subclass 对象时，变量 a 和 b 是否可用？我怎样才能坚持a和b？

public Superclass {

    private int a;
    private Obj b;

    // ... 
}

@Entity
public Subclass extends Superclass{
    @id int x;

    public Subclass(int a, Obj b, int x){
        super(a, b);
    }
}

Answer 1

a 和 b 将不会被持久化。

来自https://docs.oracle.com/javaee/6/tutorial/doc/bnbqn.html

Non-Entity Superclasses

Entities may have non-entity superclasses, and these superclasses can be either abstract or concrete. The state of non-entity superclasses is nonpersistent, and any state inherited from the non-entity superclass by an entity class is nonpersistent. Non-entity superclasses may not be used in EntityManager or Query operations. Any mapping or relationship annotations in non-entity superclasses are ignored.