如何在Spring DATA JPA中使用UUID生成器？

Question

我想加入两个模型，都使用org。冬眠主键的id.UUIDGenerator。但在启动时，我得到以下错误：

组织。冬眠工具模式。spi。CommandAcceptanceException:通过JDBC语句执行DDL“alter table user_role add constraint FK5scdquo6f12cpstqai86x4biw外键（roles_role_id）references role（role_id）”时出错

你知道我做错了什么吗？

我的代码：

用户模型：

@Entity
@Table
public class User implements Serializable {

    @Id
    @GeneratedValue(generator = "uuid2")
    @GenericGenerator(name = "uuid2", strategy = "org.hibernate.id.UUIDGenerator")
    @Column(name = "user_id", columnDefinition = "VARCHAR(255)")
    private String userId;

    @Column(name = "name")
    private String name;

    @JoinTable(name = "user_role", joinColumns = @JoinColumn(name = "userId"), inverseJoinColumns = @JoinColumn(name = "roleId"))
    @ManyToMany
    private List<Role> roles;

    public User(){
        this.roles = new ArrayList<>();
    }
// Getter & Setter
}

榜样：

@Entity
@Table
public class Role implements Serializable {

    @Id
    @GeneratedValue(generator = "uuid2")
    @GenericGenerator(name = "uuid2", strategy = "org.hibernate.id.UUIDGenerator")
    @Column(name = "role_id", columnDefinition = "VARCHAR(255)")
    private String roleId;

    @Column(name = "role_name")
    private String name;

    @Column(name = "description")
    private String description;

    @ManyToMany(mappedBy = "roles")
    private List<User> users;

    public Role(){
        this.users = new ArrayList<>();
    }
// Getter & Setter
}

用户DAO：

public interface UserDAO extends JpaRepository<User, String > {
}

角色DAO：

public interface RoleDAO extends JpaRepository<Role, String > {
}

Answer 1

联接列的名称应与列名类似，而不是与模型变量名类似。在你的情况下，你应该使用

joinColumns = @JoinColumn(name = "user_id")

和

inverseJoinColumns = @JoinColumn(name = "role_id"))

不

joinColumns = @JoinColumn(name = "userId")

和

inverseJoinColumns = @JoinColumn(name = "roleId"))

也对所有联接列执行此操作