Question

类别：

class Track
{
    ...
    public virtual IDictionary<People, Role> PeopleRoles { get; set; }
}

映射：

<class name="Track" ...>
   ...
   <map name="PeopleRoles" table="track_people_role">
   <key column="track_id"/>
   <map-key-many-to-many column="people_id" class="People"/>
   <many-to-many column="role_id" class="Role"/>
  </map>
</class>

当我执行下面的代码时，我可以看到在track_people_role表中插入的行为47637,10,1

    Person p = PersonManager.GetById(10);
    Role pr = RoleManager.GetById(1);
    Track t = TrackManager.GetById(47637);

    t.PeopleRoles.Add(p, pr);
    TrackManager.Save(t);

当我以不同的角色执行上一个后，我得到“已经添加了具有相同键的项目”错误

    Person p = PersonManager.GetById(10);
    Role pr = RoleManager.GetById(2);
    Track t = TrackManager.GetById(47637);

    t.PeopleRoles.Add(p, pr);
    TrackManager.Save(t);

我可以设法插入第二行的任何想法。

编辑：
映射：

<class name="TrackPersonRole, App.Data" table="trackpeoplerole" lazy="true">
    <composite-id>
    <key-many-to-one name="Person" class="Person" column="people_id"/>
    <key-many-to-one name="Role" class="Role" column="role_id"/>
    </composite-id>
</class>

<class name="Track" ...>
 ...
 <bag name="TrackPeopleRoles">
     <key column="track_id"/>
     <one-to-many class="TrackPersonRole"/>
 </bag>
</class>


    TrackPersonRole tpr = new TrackPersonRole();
    tpr.Person = PersonManager.GetById(10);
    tpr.Role = RoleManager.GetById(2);
    entity.PeopleRoles.Add(tpr);
    TrackManager.SaveOrUpdate(entity);

生成以下更新语句，而不是插入。

UPDATE trackpeoplerole SET track_id = 47637 /* ?p0 */
WHERE people_id = 10 /* ?p1 */ AND role_id = 2 /* ?p2 */

Answer 1

错误消息是正确的：您正在向字典中添加重复的密钥。

它甚至不是来自NHibernate - 它是由Dictionary类生成的。

如果Track可以在多个Person中拥有相同的Role，则您必须将track_person_role表格映射为实体：

class Track
{
    ...
    public virtual ICollection<TrackPersonRole> PeopleRoles { get; set; }
}

class TrackPeopleRole
{
    public virtual Person Person { get; set; }
    public virtual Role Role { get; set; }
}

映射：

<class name="Track" ...>
  ...
  <bag name="TrackPeopleRoles">
    <key column="track_id"/>
    <one-to-many class="TrackPersonRole"/>
  </map>
</class>

有关inverse和cascade的详细信息，但请从此开始。

nhibernate以三元关系保存字典

1 个答案: