如何使用 nhibernate 获取 DTO 成员的集合？

发布于 2024-07-27 01:25:22 字数 531 浏览 1 评论 0原文

我需要获取填充在 DTO 中的集合属性，但我无法找到有关执行此操作的任何信息。

我尝试这样做：

ICriteria selectCriteria = Session.CreateCriteria<DataRun>()
            .SetProjection(Projections.ProjectionList()
                .Add(Projections.Property("SomeCollection"), "Collection"))
            .SetResultTransformer(Transformers.AliasToBean<MyDto>());

但 MyDto.Collection 始终为空。我做错了吗，这可能吗？

另外，我最初计划使用子查询来完成此操作，这样我就可以用其他 DTO 填充我的 DTO 集合，但这不起作用，因为子查询的结果超过 1 行（理应如此），而 Sqlit 不喜欢这样（抛出异常）。在这里做什么是正确的？

原文

I need to get a collection property populated in a DTO and I'm having trouble finding any information on doing this.

I tried to do it like this:

ICriteria selectCriteria = Session.CreateCriteria<DataRun>()
            .SetProjection(Projections.ProjectionList()
                .Add(Projections.Property("SomeCollection"), "Collection"))
            .SetResultTransformer(Transformers.AliasToBean<MyDto>());

but MyDto.Collection is always null. Am I doing this wrong, is this even possible?

Also, I had originally planned on doing this with a SubQuery so I could just fill my DTO's collection with other DTOs but this will not work because the result of the subquery has more than 1 row (as it should) and Sqlit does not like that (throws an exception). what is the right thing to do here?

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瘫痪情歌 2024-08-03 01:25:23

我使用以下语法在项目中检索了集合属性：

public IList<ChildCollectionType> GetChildObjectsByParentId(Int32 id)
{
    ISession session = GetSession();//Get NHibernate session routine
    return session.Load<ParentDTO>(id).ChildCollectionProperty;
}

其中 id 是父对象的键。

I've retrieved collection properties in my project with the following syntax:

public IList<ChildCollectionType> GetChildObjectsByParentId(Int32 id)
{
    ISession session = GetSession();//Get NHibernate session routine
    return session.Load<ParentDTO>(id).ChildCollectionProperty;
}

where id is the key of the parent object.

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丶情人眼里出诗心の 2024-08-03 01:25:23

您可以使用自定义转换。

ICriteria selectCriteria = Session.CreateCriteria<DataRun>()
            .SetProjection(Projections.ProjectionList()
                .Add(Projections.Property("SomeCollection"), "Collection"))
            .TransformUsing(new CustomTransformer());

这是您的自定义变压器实现

public class CustomTransformer : IResultTransformer
    {
        public System.Collections.IList TransformList(System.Collections.IList collection)
        {
            return collection;
        }

        public object TransformTuple(object[] tuple, string[] aliases)
        {
            return new MyDto
            {
                //map your data to dto and convert to data type if needed
                YourProperty1 = tuple[0],
                YourProperty12 = (int)tuple[1]
            };
        }
    }

You may use custom transformation.

ICriteria selectCriteria = Session.CreateCriteria<DataRun>()
            .SetProjection(Projections.ProjectionList()
                .Add(Projections.Property("SomeCollection"), "Collection"))
            .TransformUsing(new CustomTransformer());

Here is your custom transformer implementation

public class CustomTransformer : IResultTransformer
    {
        public System.Collections.IList TransformList(System.Collections.IList collection)
        {
            return collection;
        }

        public object TransformTuple(object[] tuple, string[] aliases)
        {
            return new MyDto
            {
                //map your data to dto and convert to data type if needed
                YourProperty1 = tuple[0],
                YourProperty12 = (int)tuple[1]
            };
        }
    }

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