ManyToMany 删除

@Entity
@Data
@Table(name="dev_network")
public class DevNetwork implements Serializable {

    // ID
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Column(name = "id")
    private Long id;



    // user id
    private Long uid;

    // data
    @Column(name = "data",columnDefinition="text")
    private String data;


   // JoinTable =>    dev_network + users_networks + user   =>
   //                      id              =    dev_network_id     user_id =  id
   //                    {id,uid,data} +{dev_network_id,user_id} +{id,create_time,...}
    @JsonIgnore
    @ManyToMany
    @JoinTable(name = "users_networks", joinColumns = {@JoinColumn(name = "dev_network_id",referencedColumnName = "id")}, inverseJoinColumns =
{@JoinColumn(name = "user_id",referencedColumnName = "id")})
    private Set<User> users;

...

}


@Entity
@Getter
@Setter
@Table(name="user")
public class User implements Serializable {

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @NotNull(groups = Update.class)
    private Long id;


    @Column(name = "create_time")
    @CreationTimestamp
    private Timestamp createTime;

    @Column(name = "last_password_reset_time")
    private Date lastPasswordResetTime;

    @ManyToMany
    @JoinTable(name = "users_roles", joinColumns = {@JoinColumn(name = "user_id",referencedColumnName = "id")}, inverseJoinColumns = {@JoinColumn(name = "role_id",referencedColumnName = "id")})
    private Set<Role> roles;

    @ManyToMany(mappedBy="users") // 这里是user表，mappedBy="users" 表示关系由dev_network    维护。
    private Set<DevNetwork> networks;
}


// 根据  dev_network 的 id 删除  dev_network,中间表关系也会自动删除
devNetworkRepository.deleteById(id);