Question

来自我的Game.java的片段：

@Entity
public class Game extends Model{

    @Id
    public Long id;

    @ManyToOne
    public User user;

    @ManyToMany(cascade = CascadeType.ALL)
    public List<Checkpoint> visitedCheckpoints = new ArrayList<Checkpoint>();

    @ManyToMany(cascade = CascadeType.ALL)
    public List<Checkpoint> answeredCheckpoints = new ArrayList<Checkpoint>();
}

在自动SQL演变中，Play只创建了一个多对多关系表：game_checkpoint，只有两列是外键：game_id和checkpoint_id。这会导致错误：我添加了一个访问检查点，但由于主键约束违规，我无法添加相同的检查点，因为主键约束违规。

如何强制Play使用两个表生成SQL：game_visitedcheckpoint和game_answeredcheckpoint以后我可以单独操作两个检查点列表？

Answer 1

通过明确定义表名来解决这个问题：

@Entity
public class Game extends Model{

    @Id
    public Long id;

    @ManyToOne
    public User user;

    @ManyToMany(cascade = CascadeType.ALL)
    @JoinTable(name="game_visitedcheckpoint")
    public List<Checkpoint> visitedCheckpoints = new ArrayList<Checkpoint>();

    @ManyToMany(cascade = CascadeType.ALL)
    @JoinTable(name="game_answeredcheckpoint")
    public List<Checkpoint> answeredCheckpoints = new ArrayList<Checkpoint>();
}

Play Framework为两个“多对多”关系生成了一个表

1 个答案: