使用带有Ebean的ManyToOne映射的EmbeddedId时重复列

Question

我有一个名为"EventCheckin"的模型,它具有到"事件"和"用户"的ManyToOne映射."EventCheckin"表的PrimaryKey是用户的id和事件的id.我试图在我的EventCheckin模型中使用"EmbeddedId"来表示这一点,但是当我尝试保存EventCheckin时,它会尝试将user_id和event_id值放入表中两次,这显然会失败:

Caused by: org.h2.jdbc.JdbcSQLException: Duplicate column name "USER_ID"; SQL statement:
insert into eventCheckin (event_id, user_id, latitude, longitude, user_id, event
_id) values (?,?,?,?,?,?) [42121-158]

EventCheckin课程:

@Entity
@Table(name="eventCheckin")
public class EventCheckin extends Model
{
    @EmbeddedId public CheckinId id;

    @MapsId("userId")
    @JoinColumn(name="user_id")
    @ManyToOne public User user;

    @MapsId("eventId")
    @JoinColumn(name="event_id")
    @ManyToOne public Event event;

    .....
}

CheckinId EmbeddedId类::

@Embeddable 
public class CheckinId implements Serializable
{
    public Long eventId;  
    public String userId;
    .....
}

我的EventCheckin数据库表定义如下:

create table eventCheckin (
    user_id                   varchar(255) not null,
    event_id                  bigint not null,
    latitude                  float,
    longitude                 float,
    constraint pk_eventCheckIn primary key (user_id,event_id),
    foreign key (user_id) references user (email),
    foreign key (event_id) references event (id)
);

Answer 1

看来您尝试通过 @MapsId 和 @EmbeddedId 做同样的事情。一种（可行的）选择是选择 IdClass（等于、哈希码、额外属性等被删除）：

    @Entity
    public class User {
        @Id public String id;
    }

    @Entity
    public class Event {
        @Id public long id;
    }

    public class CheckinId implements Serializable {
        public Long event;
        public String user;
    }

    @Entity
    @IdClass(CheckinId.class)
    @Table(name="eventCheckin")
    public class EventCheckin {

        @Id
        @JoinColumn(name="user_id")
        @ManyToOne public User user;

        @Id
        @JoinColumn(name="event_id")
        @ManyToOne public Event event;
    }