java - Hibernate 给出无法确定类型错误

Question

我有一个 Roles 表，其中包含 id 和角色名称，以及一个 users 表，其中包含 role_id。我想加入这些，但收到错误无法确定类型:com.aon04.backend.models.Role，表:用户，列:[org.hibernate.mapping.Column(role)] 当我尝试这样做时。

这是我的榜样:

@Entity
@Table(name = "roles")

public class Role {
    @Id
    @GeneratedValue()
    @Column(name = "id")
    private int id;

    public int getId() {
        return id;
    }

    public void setId(int id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    @ManyToOne(fetch = FetchType.LAZY)
    @JoinColumn(name = "id", nullable = false)
    @JsonIgnore
    public User user;

    @Column(name = "name", nullable = false)
    private String name;

}

这是我的用户模型:

@Entity
@Table(name = "users")
public class User implements Serializable {
    @Id
    @GeneratedValue()
    @Column(name = "id")
    private int id;

    public Role role;

    public String getStudentNumber() {
        return studentNumber;
    }

    public void setStudentNumber(String studentNumber) {
        this.studentNumber = studentNumber;
    }

    @Column(name = "student_number", nullable = true)
    private String studentNumber;

    @Column(name = "first_name", nullable = true)
    private String firstName;

    @Column(name = "last_name", nullable = true)
    private String lastName;

    @Column(name = "email", nullable = true, unique = true)
    private String email;

    @OneToOne(fetch = FetchType.LAZY, mappedBy = "user")
    private FinishedExam finishedExam;

    @JsonIgnore
    @Column(name = "password", nullable = true)
    private String password;


    @Column(name = "created_at")
    private LocalDateTime createdAt;

    @Column(name = "updated_at")
    private LocalDateTime updatedAt;


    @ManyToMany(fetch = FetchType.LAZY)
    @JoinTable(
            name = "event_users",
            joinColumns = @JoinColumn(name = "user_id", referencedColumnName = "id"),
            inverseJoinColumns = @JoinColumn(name = "event_id", referencedColumnName = "id")
    )

    @PreUpdate
    protected void onUpdate() {
        updatedAt = LocalDateTime.now();
    }

    @PrePersist
    protected void onCreate() {
        createdAt = LocalDateTime.now();
        updatedAt = createdAt;
    }

    public int getId() {
        return id;
    }

    public void setId(int id) {
        this.id = id;
    }

    public String getFirstName() {
        return firstName;
    }

    public void setFirstName(String firstName) {
        this.firstName = firstName;
    }

    public String getLastName() {
        return lastName;
    }

    public void setLastName(String lastName) {
        this.lastName = lastName;
    }

    public String getEmail() {
        return email;
    }

    public void setEmail(String email) {
        this.email = email;
    }

    public String getPassword() {
        return password;
    }

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


    public LocalDateTime getCreatedAt() {
        return createdAt;
    }

    public void setCreatedAt(LocalDateTime createdAt) {
        this.createdAt = createdAt;
    }

    public LocalDateTime getUpdatedAt() {
        return updatedAt;
    }

    public void setUpdatedAt(LocalDateTime updatedAt) {
        this.updatedAt = updatedAt;
    }

    public Role getRole() {
        return role;
    }

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

我不知道我做错了什么。我想要的输出是当我检索用户的 JSON 时，我希望显示名称为角色的用户数据。

Answer 1

您的模型中存在不一致之处:Role 具有一个具有 ManyToOne 关系的 User，因此您的 User 应该具有以下集合: 角色您没有将您的角色映射到用户中，请通过添加双向关系来实现:

@OneToMany(mappedBy = "user")
private List<Role> role = new ArrayList<>();