实体框架不会保存数据库中的更改

When I try to add an item into the database, after running the app the data won't be in the database for long time memory. I don't know why, the connection is good and I already checked it many times.

当我尝试将项目添加到数据库中时,在运行应用程序后,数据将不会在数据库中长时间存储。我不知道为什么,连接很好,我已经多次检查过了。

 private void InsertIncomeBtn_Click(object sender, RoutedEventArgs e)
 {
     float lf = (float)Convert.ToDouble(IncomeText.Text);
     MessageBox.Show(lf.ToString());

     DateTime date = (DateTime)MovDatePick.SelectedDate;
     Movments mv1 = new Movments();
     mv1.Sum = lf;
     mv1.Date = date.Date;

     db.TotalAll.FirstOrDefault().CurrentSum += lf;
     db.Movments.Add(mv1);
     db.SaveChanges();

     IncomeWin.Close();
     MainWindow m = new MainWindow();
     m.Show();
}

I am using VS 2017 Community and writing a WPF app.

我正在使用VS 2017社区并编写WPF应用程序。

Thank for helping.

谢谢你的帮助。

1 个解决方案

#1

I'm assuming (from a lot of previous questions) that you have a SQL Server database, and your connection string most likely contains an AttachDbFileName=..... entry - correct?

我假设(从很多以前的问题)你有一个SQL Server数据库,你的连接字符串很可能包含AttachDbFileName = .....条目 - 对吗?

If so: the whole AttachDbFileName= approach is flawed - at best! When running your app in Visual Studio, it will be copying around the .mdf file (from your App_Data directory to the output directory - typically .\bin\debug - where you app runs) and most likely, your INSERT works just fine - but you're just looking at the wrong .mdf file in the end!

如果是这样:整个AttachDbFileName =方法是有缺陷的 - 充其量!在Visual Studio中运行应用程序时,它将复制.mdf文件(从App_Data目录到输出目录 - 通常是。\ bin \ debug - 应用程序运行的地方)并且很可能,你的INSERT运行正常 - 但是你最后只是看错了.mdf文件!

If you want to stick with this approach, then try putting a breakpoint on the myConnection.Close() call - and then inspect the .mdf file with SQL Server Mgmt Studio Express - I'm almost certain your data is there.

如果你想坚持这种方法,那么尝试在myConnection.Close()调用上设置一个断点 - 然后用SQL Server Mgmt Studio Express检查.mdf文件 - 我几乎可以肯定你的数据在那里。

The real solution in my opinion would be to

我认为真正的解决方案是

install SQL Server Express (and you've already done that anyway)

安装SQL Server Express(你已经完成了)
install SQL Server Management Studio Express

安装SQL Server Management Studio Express
create your database in SSMS Express, give it a logical name (e.g. YourDatabase)

在SSMS Express中创建数据库,为其指定一个逻辑名称(例如YourDatabase)
connect to it using its logical database name (given when you create it on the server) - and don't mess around with physical database files and user instances. In that case, your connection string would be something like:

使用其逻辑数据库名称(在服务器上创建时给定)连接到它 - 并且不要乱用物理数据库文件和用户实例。在这种情况下,您的连接字符串将是这样的:
```
Data Source=.\\SQLEXPRESS;Database=YourDatabase;Integrated Security=True
```
and everything else is exactly the same as before...

其他一切都和以前完全一样......

Also see Aaron Bertrand's excellent blog post Bad habits to kick: using AttachDbFileName for more background info.

另请参阅Aaron Bertrand的优秀博客文章Bad bad to kick:使用AttachDbFileName获取更多背景信息。

#1