实体Bean（JPA）中的单向关系

@OneToMany

@Entitypublic class Customer {  @Id  @Column(name="cust_id")  private long id;  ...  @oneToMany  @JoinColumn(name="owner_id", referencedColumnName="cust_id")  private List<Order> order;  ...}@Entitypublic class Order {    @Id    @Column(name="order_id")    private long id;    ...}

关系型数据库：

顾客：

+---------+---------+------+-----+---------+-------+| Field   | Type    | Null | Key | Default | Extra |+---------+---------+------+-----+---------+-------+| cust_id | int(11) | NO   | PRI | NULL    |       |+---------+---------+------+-----+---------+-------+

订购：

+----------+---------+------+-----+---------+-------+| Field    | Type    | Null | Key | Default | Extra |+----------+---------+------+-----+---------+-------+| order_id | int(11) | NO   | PRI | NULL    |       || owner_id | int(11) | NO   | MUL | NULL    |       |+----------+---------+------+-----+---------+-------+