使用Entity Framework 6创建计算属性 [英] Creating a computed property with Entity Framework 6

问题描述

我正在使用数据库优先方法，并且已经从数据库创建了模型.现在，我的Winforms应用程序中有一个datagrid视图，该视图已绑定到绑定源.一切正常(适当的数据显示在datagrid视图中).现在的问题是，如何添加一个包含两个值的计算属性(已在db中找到)?例如:

I am using Database First approach and I have created model from a database. Now I have a datagrid view in my Winforms app, that is bound to a binding source. And all that works fine (an appropriate data is shown in datagrid view). Now the problem is, how to add a computed property that consists of two values (already found in db) ? For an example:

让我们说我有一个表用户(id，用户名，first_name，last_name，user_type)，但是我想在绑定的datagrid视图中有不同的列，并且我想拥有这些列:

Lets say that I have a table user (id, username, first_name, last_name, user_type) but I want to have different columns in my bound datagrid view, and I want to have these columns:

username, full name, type

其中"full name"是我使用first_name + " " + last_name会得到的.

where "full name" is what would I get with first_name + " " + last_name.

我想我不能像这样手动修改模型类:

I guess I can't just modify a model class manually like this:

public string FullName
{
    get
    {
        return FirstName + " " + LastName;
    }
    protected set {}
}

因为此类是自动生成的，并且每次从现有数据库生成模型时(当我进行一些更改时)，我的代码都会被删除，因此这不是真正的选择...

because this class is generated automatically , and my code will be deleted each time a generate models from an existing database (when I make some change), so this is not the real option...

推荐答案

实际上，我通过使用部分类功能解决了此问题: 我创建了另一个文件，该文件包含User模型类的另一部分(带有我的其他属性)，一切正常.

Actually, I solved this by using partial class functionality: I have created another file that contains another portion of my User model class (with my additional properties) and everything went just fine.

namespace User.Model
{
    public partial class User
    {
        public string FullName
        {
            get
            {
                return (this.firstName + " " + this.lastName;
            }
            protected set { }
        }
    }
}

现在，当我生成模型类时，此新文件不受EF的影响.另外，这个新字段也可以通过datagrid视图正确显示...

Now when I generate model classes, this new file is not affected by EF. Also this new field is correctly shown by datagrid view...

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