为什么我的SubmitChanges()在LINQ-to-SQL中不起作用?

问题描述

我在WPF应用程序中创建了一个.MDF数据库.

I created a .MDF database in my WPF application.

然后我生成了LINQ-to-SQL类，并使用LINQ获得了所有客户.

I then generated LINQ-to-SQL classes and used LINQ get all the customers.

然后我浏览它们并更改它们的每个姓氏.

Then I run through them and change each of their last names.

但是，当我调用SubmitChanges时，数据库保持不变.

However, when I call SubmitChanges, the database remains unchanged.

我认为这是SubmitChanges()的目的，用于将更改提交到数据库?

I thought that was the purpose of SubmitChanges(), to submit changes to the database?

我缺少什么，如何提交更改"回到我的数据库?

What am I missing, how do I "submit changes" back to my database?

public Window1()
{
    InitializeComponent();

    Main2DataContext _db = new Main2DataContext();
    var customers = from c in _db.Customers
                    select c;

    foreach (var customer in customers)
    {
        customer.LastName = "CHANGED lastname"; //ListBox shows changes
    }

    _db.SubmitChanges(); //does NOT save to database (???)

}

推荐答案

我想我知道问题出在哪里.您是否正在使用本地.mdf文件?如果是这种情况，请检查您的bin/debug文件夹.我敢打赌，您那里有一个包含更改的数据库.我认为您的项目中有一个.mdf文件，每次构建时都会将其复制到bin/debug文件夹中.因此，更改已保存到副本中，而直接在项目中的副本中看不到更改.

I think I know what the problem is. Are you using a local .mdf file? If that's the case, check your bin/debug folder. I bet you have a database in there with the changes. I think you have an .mdf file in your project that is getting copied to the bin/debug folder everytime you build. Therefore the changes are getting saved to the copy, and you're not seeing it reflected in the copy that resides directly in your project.

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