我正在尝试映射具有多对多关系的 Person 和 Address 类。我想将 Address 集合映射为 IDictionary,并将 Address 属性 Type 作为键。该关系仅从 Person 端映射。
public class Person
{
public IDictionary<int, Address> Addresses { get; set; }
}
public class Address
{
public int Type { get; set; }
}
我使用的映射是:
HasManyToMany<Address>(x => x.Addresses).Table("PersonAddress")
.ParentKeyColumn("PersonId").ChildKeyColumn("AddressId")
.AsMap(x => x.Type);
问题是发出的SQL是:
SELECT addressesd0_.PersonId as PersonId1_,
addressesd0_.AddressId as AddressId1_,
addressesd0_.Type as Type1_,
address1_.AddressId as AddressId5_0_
-- etc.
FROM dbo.PersonAddress addressesd0_
left outer join dbo.Address address1_
on addressesd0_.AddressId = address1_.AddressId
WHERE addressesd0_.PersonId = 420893
它正在尝试从不存在的多对多连接表中选择类型。我尝试了多种映射变体,但均未成功。
我该如何映射它?
最佳答案
这是不可能的。字典需要关系表中的键值。您拥有的表结构是一个简单的多对多包或集合。
我要做的,是将其映射为普通包或集,并在实体中提供类似字典的访问:
public class Person
{
private IList<Address> addresses;
public IEnumerable<Address> Addresses { get { return addresses; } }
public Address GetAddressOfType(int addressType)
{
return addresses.FirstOrDefault(x => x.Type == addressType);
}
public void SetAddress(Address address)
{
var existing = GetAddressOfType(address.Type);
if (existing != null)
{
addresses.Remove(existing);
}
addresses.Add(address);
}
}
关于nhibernate - 将多对多关系映射为 IDictionary,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/7071093/