实体框架未将更改保存到本地数据库

Question

I'm new to C# and Entity Framework and I'm trying to write an application to improve my knowledge.

I think I've set up everything correctly and I don't get any type of error. The problem is that I can not add a new record to localDb in Visual Studio 2017.

Any ideas? Thanks in advance.

Here is my code

private void Save_btn_Click(object sender, EventArgs e)
{
        var context = new Database1Entities();

        var aMemberdef = new Members()
        {
            FirstName = Name_txt.Text,
            LastName = LastName_txt.Text
        };

        context.Members.Add(aMemberdef);
        context.SaveChanges();
}

and here my app.config :

<?xml version="1.0" encoding="utf-8"?>
<configuration>
    <configSections>
        <section name="entityFramework" 
                 type="System.Data.Entity.Internal.ConfigFile.EntityFrameworkSection, EntityFramework, Version=6.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" 
                 requirePermission="false" />
    </configSections>
    <startup>
        <supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.5.2" />
    </startup>
    <connectionStrings>
        <add name="Database1Entities" 
             connectionString="metadata=res://*/EF.Model1.csdl|res://*/EF.Model1.ssdl|res://*/EF.Model1.msl;provider=System.Data.SqlClient;provider connection string=&quot;data source=(LocalDB)\MSSQLLocalDB; attachdbfilename=|DataDirectory|\Data\Database1.mdf; initial catalog=Database1; integrated security=True;MultipleActiveResultSets=True;App=EntityFramework&quot;" 
             providerName="System.Data.EntityClient" />
    </connectionStrings>
    <entityFramework>
        <defaultConnectionFactory  
             type="System.Data.Entity.Infrastructure.SqlConnectionFactory, EntityFramework" />
        <providers>
            <provider invariantName="System.Data.SqlClient" 
                      type="System.Data.Entity.SqlServer.SqlProviderServices, EntityFramework.SqlServer" />
        </providers>
    </entityFramework>
</configuration>

I think there is some mistake in the app config file but the connection string was generated by entity framework. So I'm stuck MyDB Structure

Answer 1

Because your localdb is copied to bin folder every time you run it. It gets overwritten everytime you run/debug it. Main file in the project folder is not updated. For detailed answer: https://social.msdn.microsoft.com/Forums/en-US/393bddc6-0b85-4c27-9475-27172e50d2d9/entity-framework-doesnt-save-new-record-into-database?forum=adodotnetentityframework