Subsonic 3 - 序列不包含匹配元素

发布于 2024-09-03 22:44:51 字数 909 浏览 5 评论 0原文

我需要帮助创建亚音速 LINQ SQL。首先是基础知识，这工作正常：

var query = (from o in bd.concelhos
                     orderby o.descricao
                     select o);

        var results = query.ToList<concelhos>();

但是，我想过滤掉一些列，并且我创建了以下代码：

var query = (from o in bd.concelhos
                     orderby o.descricao
                     select new FilteredConcelhos { id = o.idDistrito + "/" + o.idConcelho, descricao = o.descricao });

        var results = query.ToList<FilteredConcelhos>();

在 ToList 方法中出现错误，并带有描述“序列不包含匹配元素”

任何帮助都会很好。 ..

更新：原来我在新声明的类中缺少 get set 属性...... 像这样

public class FilteredConcelhos
{
    public string id { get; set; }
    public string descricao { get; set; }
}

这清除了异常，但生成的列表仍然全部错误（FilteredConcelhos.id 不包含任何内容，而 FilteredConcelhos.descricao 包含数字）

原文

I need help creating a LINQ SQL with subsonic. First the basics, this works fine:

var query = (from o in bd.concelhos
                     orderby o.descricao
                     select o);

        var results = query.ToList<concelhos>();

However, I want to filter out some columns and I have created the following code:

var query = (from o in bd.concelhos
                     orderby o.descricao
                     select new FilteredConcelhos { id = o.idDistrito + "/" + o.idConcelho, descricao = o.descricao });

        var results = query.ToList<FilteredConcelhos>();

which errors out in the ToList method with the description "Sequence contains no matching element"

Any help would be great with this...

update:
Turns out I was missing get set attributes in the newly declared class...
Like so

public class FilteredConcelhos
{
    public string id { get; set; }
    public string descricao { get; set; }
}

This clears the exception, but the resulting List is still all wrong (FilteredConcelhos.id contains nothing and FilteredConcelhos.descricao contains numbers)

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和我恋爱吧 2024-09-10 22:44:58

不幸的是，这种情况在我身上发生过很多次。我不确定 Linq 2 Object 如何工作的细节，但如果您对原始对象调用 ToList，如下所示：

from o in bd.concelhos.ToList()
...

它应该可以解决问题。

Unfortunately, this happened to me a lot. I'm not sure about the details of how Linq 2 Object works, but if you'll call ToList on the original object, like this:

from o in bd.concelhos.ToList()
...

It should do the trick.

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风轻花落早 2024-09-10 22:44:56

您是否尝试过使用匿名类型？

var query = (from o in bd.concelhos
                 orderby o.descricao
                 select new { id = o.idDistrito + "/" + o.idConcelho, 
                              descricao = o.descricao });

var results = query.ToList();

Have you tried to work with an anonymous type?

var query = (from o in bd.concelhos
                 orderby o.descricao
                 select new { id = o.idDistrito + "/" + o.idConcelho, 
                              descricao = o.descricao });

var results = query.ToList();

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