一对多查询可以用注解`@OneToMany`来完成，默认为`left join`语句。 反过来就是多对一查询，可以用注解`@ManyToOne`来完成。 ```java public class Person implements Serializable { /** * person：对应 BankCard#person 变量名称. */ @OneToMany(mappedBy = "person", fetch = FetchType.EAGER) private List<BankCard> bankCardList; } ``` ```java public class BankCard implements Serializable { /** * referencedColumnName：对应 Person#id 主键变量名称. * 将会在表 BankCard 建立物理外键 person_id. */ @ManyToOne(targetEntity = Person.class) @JoinColumn(name = "person_id", referencedColumnName = "id") private Person person; } ```