Question

我想将班级地址映射到班级员工，我所做的事情如下所示。

我的员工班

@Entity(name = "EMPLOYEE")
public class Employee  {
    @Id @GeneratedValue
    @Column(name="EMPLOYEEID", length =30)
    int id;
    public Employee(String string, String string2,String string3, String string4) {
    this.name=string;
    this.age=string2;
    }
    public int getId() {
        return id;
    }
    public void setId(int id) {
        this.id = id;
    }
    @Column(name="NAME", length = 30)
    String name;
    @Column(name="AGE",  length = 30)
    String age;
    @OneToOne(mappedBy = "employee", cascade = CascadeType.ALL)
    Address address;
    public Address getAddress() {
        return address;
    }
    public void setAddress(Address address) {
        this.address = address;
    }
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public String getAge() {
        return age;
    }
    public void setAge(String age) {
        this.age = age;
    }

我的地址类是

@Entity(name="Address")
public class Address {
    @Id
    @Column(name="EMPLOYEEID", length =30)
    @GenericGenerator(name="generator", strategy="foreign", parameters = @Parameter(name="property", value="employee"))
    @GeneratedValue(generator="generator")
    int id;
    @Column(name="LINE1", length=30)
    String line1;
    @Column(name="LINE2", length=30)
    String line2;
    @Column(name="LINE3", length=30)
    String line3;
    public String getLine1() {
        return line1;
    }
    public void setLine1(String line1) {
        this.line1 = line1;
    }
    public String getLine2() {
        return line2;
    }
    public void setLine2(String line2) {
        this.line2 = line2;
    }
    public String getLine3() {
        return line3;
    }
    public void setLine3(String line3) {
        this.line3 = line3;
    }
}

但是每当我试图执行它时，我都会收到错误

未知的mappedBy in：com.hibernatetest.company.Employee.address，引用的属性unknown：com.hibernatetest.company.Address.employee

我在这里做错了什么？

Answer 1

您引用了Address的不存在的属性：

@OneToOne(mappedBy = "employee", cascade = CascadeType.ALL)
Address address;

查看OneToOne.mappedBy()的文档：

（可选）拥有该关系的字段。此元素仅在关联的反向（非拥有）侧指定。

因此，您的代码声明Address实体拥有拥有该关系的字段employee。但它没有这样的财产。

可能您可以使用以下代码实现此属性（免责声明：我没有对其进行测试，而且我不知道它是否适合您的特定情况）：

@OneToOne(optional=false)
@JoinColumn(name="EMPLOYEEID")
Employee employee;

public Employee getEmployee() {
     return employee;
}

Answer 2

我认为你的未知是因为你给了小写字母的员工，但没有在任何地方尝试将其改为

@OneToOne(mappedBy = "EMPLOYEE", cascade = CascadeType.ALL) here

Hibernate - 使用注释进行一对一映射

2 个答案: