一对一外键

Question

我在项目中有一对一外键关系映射的问题。

User.java

@Access(AccessType.FIELD)
@Entity
@Table(name = "users")
public class User {
public Role ro;

@Id
@GeneratedValue(strategy = GenerationType.AUTO)
public int user_id;
@Column(name = "username")
public String username;
@Column(name = "password")
public String password;


@OneToOne(cascade = CascadeType.ALL)
@JoinColumn(name = "username")
public Role getRo() {
    return ro;
}

public void setRo(Role ro) {
    this.ro = ro;
}

@Column(name = "enabled")

public int enabled;


public User() {
}

public int getUser_id() {
    return user_id;
}

public User(String username, String password, int enabled) {
    this.username = username;
    this.password = password;
    this.enabled = enabled;

}


public String getUsername() {
    return username;
}

public void setUsername(String username) {
    this.username = username;
}

public String getPassword() {
    return password;
}

public void setPassword(String password) {
    this.password = password;
}

public int getEnabled() {
    return enabled;
}

public void setEnabled(int enabled) {
    this.enabled = enabled;
}



@Override
public String toString() {
    return String.format(
            "student[id=%d, name='%s', age='%d']",
            ro.getUsername(), username, ro.getUsername());
}

}

角色Java语言

import javax.persistence.*;

@Access(AccessType.FIELD)
@Entity
@Table(name = "user_roles")
public class Role {

@Id
@GeneratedValue(strategy = GenerationType.AUTO)
public int user_role_id;
@Column(name = "username")
public String username;
@Column(name = "role")
public String role;

public User user;


@OneToOne(mappedBy = "ro")
public User getUser() {
    return user;
}

public void setUser(User user) {
    this.user = user;
}



public Role(String username, String role) {
    this.username = username;
    this.role = role;
}

public Role() {
}

public int getUser_role_id() {
    return user_role_id;
}



public String getUsername() {
    return username;
}

public void setUsername(String username) {
    this.username = username;
}

public String getRole() {
    return role;
}

public void setRole(String role) {
    this.role = role;
}



}

这是错误：

导致原因：lass.validateMappingException：无法确定类型：lass.java:265角色，在表：用户，对于列：[inal.jar列（ro）]在org.hibernate.boot.internal.SimpleVmpl.validate类型（SimpleVmpl.java:329）~[hibernate-core-5.0.12。Final.jar：5.0.12。最终]在org.hibernate.mapping.SimpleValue.is有效（SimpleValue.java:398）~[hibernate-core-5.0.12。Final.jar：5.0.12。最终]在Porg.hibernate.mapping.roperty.is有效（Property.java:225）~[hibernate-core-5.0.12。Final.jar：5.0.12。最终]在org.hibernate.mapping.持续lass.validate（持续lass.java:595）~[Hibernate-core-5.0.12。Final.jar：5.0.12。最终]在org.hibernate.mapping.RootCorg.hibernate.（RootCcom.company.project.models.）~[Hibernate-core-5.0.12。Forg.hibernate.mapping.：5.0.12。最终]在org.hibernate.mapping.MetadataIalue.get（MetadataIalue.java:431）~[Hibernate-core-5.0.12。F：5.inal.jar0最后]...省略了22个常见帧

Answer 1

您应该在变量声明或getter（）s上注释所有@Collie/@OneToOne。这就是为什么hibernate在类User中找不到Role。