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[英]Nhibernate Query Over Map Entity List of Object Property To Comma Seperated DTO String Propery Using AliasToBean Transformer
[英]NHibernate AliasToBean transformer associations
我正在嘗試使用以下語句來獲取具有我所追求的字段的實體:
retVal = session.CreateCriteria(typeof(MyEntity))
.CreateAlias("MyEntityProperty", "MyEntityProperty")
.Add(Restrictions.Eq("MyEntityProperty.Year", year))
.SetProjection(
Projections.Distinct(
Projections.ProjectionList()
.Add(Projections.Property("Property1"), "Property1")
.Add(Projections.Property("Property2"), "Property2")
.Add(Projections.Property("MyEntityProperty.RegisteredUser"), "MyEntityProperty.RegisteredUser")
.Add(Projections.Property("MyEntityProperty.CompanyInfo"), "MyEntityProperty.CompanyInfo")
)
)
.SetResultTransformer(Transformers.AliasToBean(typeof(MyEntity)))
.List<MyEntity>()
.Cast<BaseMyEntity>();
MyEntity是我想要返回的實體,MyEntityProperty是MyEntity的一個屬性,它是另一個實體(MyEntityProperty類型)。
我得到的錯誤是Could not find a setter for property 'MyEntityProperty.RegisteredUser' in class 'MyEntity'
AliasToBean轉換器是否無法處理子實體? 或者還有什么我需要做的才能讓它發揮作用?
有我的主要作品 ......我用它來改變任何級別的投影深度。 拿它並像這樣使用它:
.SetResultTransformer(new DeepTransformer<MyEntity>())
它可以用於任何ValueType
屬性, many-to-one
引用以及動態對象 ......
public class DeepTransformer<TEntity> : IResultTransformer
where TEntity : class
{
// rows iterator
public object TransformTuple(object[] tuple, string[] aliases)
{
var list = new List<string>(aliases);
var propertyAliases = new List<string>(list);
var complexAliases = new List<string>();
for(var i = 0; i < list.Count; i++)
{
var aliase = list[i];
// Aliase with the '.' represents complex IPersistentEntity chain
if (aliase.Contains('.'))
{
complexAliases.Add(aliase);
propertyAliases[i] = null;
}
}
// be smart use what is already available
// the standard properties string, valueTypes
var result = Transformers
.AliasToBean<TEntity>()
.TransformTuple(tuple, propertyAliases.ToArray());
TransformPersistentChain(tuple, complexAliases, result, list);
return result;
}
/// <summary>Iterates the Path Client.Address.City.Code </summary>
protected virtual void TransformPersistentChain(object[] tuple
, List<string> complexAliases, object result, List<string> list)
{
var entity = result as TEntity;
foreach (var aliase in complexAliases)
{
// the value in a tuple by index of current Aliase
var index = list.IndexOf(aliase);
var value = tuple[index];
if (value.IsNull())
{
continue;
}
// split the Path into separated parts
var parts = aliase.Split('.');
var name = parts[0];
var propertyInfo = entity.GetType()
.GetProperty(name, BindingFlags.NonPublic
| BindingFlags.Instance
| BindingFlags.Public);
object currentObject = entity;
var current = 1;
while (current < parts.Length)
{
name = parts[current];
object instance = propertyInfo.GetValue(currentObject);
if (instance.IsNull())
{
instance = Activator.CreateInstance(propertyInfo.PropertyType);
propertyInfo.SetValue(currentObject, instance);
}
propertyInfo = propertyInfo.PropertyType.GetProperty(name, BindingFlags.NonPublic | BindingFlags.Instance | BindingFlags.Public);
currentObject = instance;
current++;
}
// even dynamic objects could be injected this way
var dictionary = currentObject as IDictionary;
if (dictionary.Is())
{
dictionary[name] = value;
}
else
{
propertyInfo.SetValue(currentObject, value);
}
}
}
// convert to DISTINCT list with populated Fields
public System.Collections.IList TransformList(System.Collections.IList collection)
{
var results = Transformers.AliasToBean<TEntity>().TransformList(collection);
return results;
}
}
好吧,我不是把事情變得比必要的更復雜。
我不需要嘗試在子實體上設置字段,而是引用實體字段本身:
.Add(Projections.Property("MyEntityProperty"), "MyEntityProperty")
和nHibernate填充它很好。
但我很高興我問,因為我得到了Radim非常有用的代碼:-)
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