NHibernate Criteria Queries - 如何在一对一关系中使用
我有简单的 3 个 POCO 类:
public class User
{
//PK
public virtual int UserId { get; set; }
//ONE to ONE
public virtual Profil Profil{ get; set; }
//ONE to MANY
public virtual IList<PhotoAlbum> Albums { get; set; }
}
public class Profil
{
//PK
public virtual int ProfilId { get; set; }
public virtual int Age { get; set; }
public virtual int Sex { get; set; }
}
public class PhotoAlbum
{
//PK
public virtual int PhotoAlbumId { get; set; }
public virtual string Name { get; set; }
public virtual int NumberOfPhoto { get; set; }
}
我创建了这些映射类:
public class UserMap : ClassMap<User>
{
public UserMap()
{
//PK
Id(p => p.UserId)
.GeneratedBy.Identity();
//FK
References(p => p.Profil)
.Column("ProfilId")
.Cascade.All();
//ONE TO MANY
HasMany(p => p.Albums)
.Cascade.All();
Table("Users");
}
}
public class ProfilMap: ClassMap<Profil>
{
public ProfilMap()
{
Id(p => p.ProfilId)
.GeneratedBy.Identity();
Map(p => p.Age)
.Not.Nullable();
Map(p => p.Sex)
Table("Profiles");
}
}
public class PhotoAlbumMap : ClassMap<PhotoAlbum>
{
public PhotoAlbumMap()
{
Id(p => p.PhotoAlbumId)
.GeneratedBy.Identity();
Map(p => p.Name)
.Not.Nullable();
Map(p => p.NumberOfPhoto)
.Not.Nullable();
Table("PhotoAlbums");
}
}
然后我用这个方法创建了简单的 NHibernate 存储库类:
public IList<T> GetItemsByCriterions(params ICriterion[] criterions)
{
ICriteria criteria = AddCriterions(_session.CreateCriteria(typeof(T)),
criterions);
IList<T> result = criteria.List<T>();
return result ?? new List<T>(0);
}
为了测试,我为某些实体创建了存储库,例如用户:
_userRepo = new NHibRepository<User>(NHibeHelper.OpenSession());
并且我希望有可能以这种方式进行查询:
var users = _userRepo.GetItemsByCriterions(new ICriterion[]
{
Restrictions.Gt("Profile.Age",10)
});
这个尝试完成时出现错误:
无法解析属性:配置文件:Repository.User
用户具有属性配置文件类型的配置文件,并且此属性具有属性 ProfileId、Age 和性。
** #1 已编辑:**
@ 我尝试了这个:
var users = _userRepo.GetItemsByCriterions(new ICriterion[]
{
Restrictions.Where<User>(u=>u.Profil.Sex==0)
});
完成后出现错误:
无法解析属性:Profil.Sex of:Repository.User
#2 EDITED
我尝试使用内森的建议:
var result = _userRepo.Session.CreateCriteria<User>()
.CreateAlias("Profile", "profile", JoinType.InnerJoin)
.Add(Restrictions.Eq("profile.Sex", 0));
IList<User> users=null;
if (result != null)
users = result.List<User>();
如果我尝试将结果转换为列表,我再次收到此错误:无法解析属性:配置文件:Repository.User
I have simple 3 POCO classes:
public class User
{
//PK
public virtual int UserId { get; set; }
//ONE to ONE
public virtual Profil Profil{ get; set; }
//ONE to MANY
public virtual IList<PhotoAlbum> Albums { get; set; }
}
public class Profil
{
//PK
public virtual int ProfilId { get; set; }
public virtual int Age { get; set; }
public virtual int Sex { get; set; }
}
public class PhotoAlbum
{
//PK
public virtual int PhotoAlbumId { get; set; }
public virtual string Name { get; set; }
public virtual int NumberOfPhoto { get; set; }
}
I created these mapping classes:
public class UserMap : ClassMap<User>
{
public UserMap()
{
//PK
Id(p => p.UserId)
.GeneratedBy.Identity();
//FK
References(p => p.Profil)
.Column("ProfilId")
.Cascade.All();
//ONE TO MANY
HasMany(p => p.Albums)
.Cascade.All();
Table("Users");
}
}
public class ProfilMap: ClassMap<Profil>
{
public ProfilMap()
{
Id(p => p.ProfilId)
.GeneratedBy.Identity();
Map(p => p.Age)
.Not.Nullable();
Map(p => p.Sex)
Table("Profiles");
}
}
public class PhotoAlbumMap : ClassMap<PhotoAlbum>
{
public PhotoAlbumMap()
{
Id(p => p.PhotoAlbumId)
.GeneratedBy.Identity();
Map(p => p.Name)
.Not.Nullable();
Map(p => p.NumberOfPhoto)
.Not.Nullable();
Table("PhotoAlbums");
}
}
Then I created simple NHibernate repository class with this method:
public IList<T> GetItemsByCriterions(params ICriterion[] criterions)
{
ICriteria criteria = AddCriterions(_session.CreateCriteria(typeof(T)),
criterions);
IList<T> result = criteria.List<T>();
return result ?? new List<T>(0);
}
For test I created repository for some entity, for example User:
_userRepo = new NHibRepository<User>(NHibeHelper.OpenSession());
and I would like have possibility make query in this style:
var users = _userRepo.GetItemsByCriterions(new ICriterion[]
{
Restrictions.Gt("Profile.Age",10)
});
this attempt finished with error:
could not resolve property: Profile of: Repository.User
User has property Profile type of Profile and this property has properties ProfileId, Age
and sex.
** #1 EDITED:**
@ I tried this:
var users = _userRepo.GetItemsByCriterions(new ICriterion[]
{
Restrictions.Where<User>(u=>u.Profil.Sex==0)
});
finished with error:
could not resolve property: Profil.Sex of: Repository.User
#2 EDITED
I tried use Nathan’s advice:
var result = _userRepo.Session.CreateCriteria<User>()
.CreateAlias("Profile", "profile", JoinType.InnerJoin)
.Add(Restrictions.Eq("profile.Sex", 0));
IList<User> users=null;
if (result != null)
users = result.List<User>();
If I tried convert result to List I again get this error: could not resolve property: Profile of: Repository.User
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查看您的示例,用户有一个配置文件属性而不是配置文件属性。
如果它应该是 Profil 那么我会将
Restrictions.Gt(Profile.Age,10)
更改为Restrictions.Gt(Profil.Age,10)
否则更改属性的名称和映射以匹配查询。编辑:
您正在尝试查询用户对象。你需要包含 CreateAlias 让 nhibernate 知道你想要链接到不同的对象。
试试这个。
Looking at your example, User has a Profil property not a Profile property.
If it is supposed to be Profil then I would change the
Restrictions.Gt(Profile.Age,10)
toRestrictions.Gt(Profil.Age,10)
otherwise change the name of the property and mapping to match the query.Edit:
You are trying to query the User Object. you need to include the CreateAlias let nhibernate know that you want to link to a different object.
Try This.