多对多关系 springboot mysql

Question

我有 2 个模型 User 和 roles ，它是多对多关系。我需要添加一个用户并给他一个已经存在于我的数据库中的特定角色。 ------用户------

@Getter
@Setter
@NoArgsConstructor
@AllArgsConstructor
@ToString

@Entity
@Table(name = "user")
public class User {
    
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Column(name="user_Id")
    private int userId;
    @Column(name="name")
    private String name;
    @Column(name="lastname")
    private String lastname;
    @Column(name="email")
    private String email;
    @Column(name="password")
    private String password;
    @Column(name="isActive")
    private boolean isActive;
    @Column(name="lastActive")
    private String lastActive;
    @Column(name="createdDate")
    private String createdDate;
    @Column(name="isBlocked")
    private boolean isBlocked;
    
    @ManyToOne(fetch = FetchType.LAZY, optional = false)
    @JoinColumn(name = "institution_id", nullable = false)
    @JsonIgnoreProperties(value = {"user"})
    private Institution institution;
    
    @ManyToMany(fetch = FetchType.LAZY, cascade = {CascadeType.PERSIST, CascadeType.DETACH,CascadeType.MERGE,CascadeType.REFRESH})
    @JoinTable(name = "user_has_role",
            joinColumns = {
                    @JoinColumn(name = "user_id", referencedColumnName = "user_id",
                            nullable = false, updatable = true)},
            inverseJoinColumns = {
                    @JoinColumn(name = "role_id", referencedColumnName = "role_id",
                            nullable = false, updatable = true)})
    @JsonIgnoreProperties(value = {"users"})
    private Set<Role> roles = new HashSet<>();

}

--------角色--------

@Getter
@Setter
@NoArgsConstructor
@AllArgsConstructor
@ToString

@Entity
@Table(name = "role")
public class Role {
    
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Column(name="role_Id")
    private int roleId;
    @Column(name="name")
    private String name;
    @Column(name="description")
    private String description;
    @ManyToMany(mappedBy = "roles", fetch = FetchType.LAZY)
    @JsonIgnoreProperties(value = {"roles"})
    private Set<User> users = new HashSet<>();

}

和应用程序的控制器

@PostMapping("/addUser")
    public String addUser(@RequestBody User user) {
        userrepository.save(user);
        return "user saved with name: " + user.getName();
    }

这是我在 api 请求中发送的 json 正文。

{
        "userId" : 7,
        "name": "test",
        "lastname": "testlast",
        "email": "testtest@yahoo.com",
        "password": "test123",
        "lastActive": "04/05/21",
        "createdDate": "02/04/20",
        "institution": {
            "institutionId": 4
            },
       "roles": [
            {
                "roleId": 2
            }
        ],  
        "active": false,
        "blocked": true
    }

我的用户有角色的一切都很好 table 添加了一条记录，其中 userId = 7 和 roleId=2 但问题是 table 角色正在更新，字段名称和描述正在被删除并替换为空值... 任何想法请

Answer 1

您已将 CascadeType.PERSIST 添加到 User 和 Role @ManyToMany 加入。
当 User 实体被持久化到 EntityManager 时，它也会持久化 Role 实体。当您在 Role 的请求负载中传递主键时，它将 create/update 角色 table.

您需要从加入中删除 CascadeType.PERSIST，它将按预期工作。

@ManyToMany(fetch = FetchType.LAZY, cascade = {CascadeType.DETACH, CascadeType.MERGE, CascadeType.REFRESH })
    @JoinTable(name = "user_has_role",
            joinColumns = {
                    @JoinColumn(name = "user_id", referencedColumnName = "user_id",
                            nullable = false, updatable = true)},
            inverseJoinColumns = {
                    @JoinColumn(name = "role_id", referencedColumnName = "role_id",
                            nullable = false, updatable = true)})
    @JsonIgnoreProperties(value = {"users"})
    private Set<Role> roles = new HashSet<>();

多对多关系 springboot mysql

many-to-many relationship springboot mysql

java

mysql

api

many-to-many

spring-boot