我是 hibernate 的新手。我试图通过以下代码在Person和PersonDetail实体之间创建一对一映射:
@Entity
public class Person {
private int personId;
private String personName;
private PersonDetail personDetail;
@OneToOne(mappedBy="person")
public PersonDetail getPersonDetail() {
return personDetail;
}
public void setPersonDetail(PersonDetail personDetail) {
this.personDetail = personDetail;
}
@Id
@GeneratedValue
public int getPersonId() {
return personId;
}
public void setPersonId(int personId) {
this.personId = personId;
}
public String getPersonName() {
return personName;
}
public void setPersonName(String personName) {
this.personName = personName;
}
}
@Entity
public class PersonDetail {
private int personDetailId;
private String zipCode;
private String job;
private double income;
private Person person;
@OneToOne(cascade=CascadeType.ALL, fetch=FetchType.EAGER)
public Person getPerson() {
return person;
}
public void setPerson(Person person) {
this.person = person;
}
@Id
@GeneratedValue
public int getPersonDetailId() {
return personDetailId;
}
public void setPersonDetailId(int personDetailId) {
this.personDetailId = personDetailId;
}
public String getZipCode() {
return zipCode;
}
public void setZipCode(String zipCode) {
this.zipCode = zipCode;
}
public String getJob() {
return job;
}
public void setJob(String job) {
this.job = job;
}
public double getIncome() {
return income;
}
public void setIncome(double income) {
this.income = income;
}
}
我希望PersonDetail应该是拥有的实体(反之亦然,但我只想测试)。我不理解的是我在Person实体中使用的mappingBy属性的用法。如果删除它,则会出现以下错误:
“无法确定com.hibernate.onetoonemapping.PersonDetail的类型,在表:Person上,对于列:[org.hibernate.mapping.Column(personDetail)]”
此mappingBy属性有什么作用?我已经读过,mappedBy属性放在非所有者的那一侧。但是它到底是做什么的呢?
最佳答案
这意味着实体之间的关系已经被映射,因此您不必重复两次。您只需使用mapledBy属性说“嘿,就在那完成了”。
关于hibernate - 注释中的mapledBy属性的含义?,我们在Stack Overflow上找到一个类似的问题:https://stackoverflow.com/questions/8962878/