C# Entity Framework Reconnecting to the database by new connection

Question

1 Run Application
2. Create Context

dbContext = new DBFirstContext();

3 Change App.config connection string for Entity FrameWork Object

Configuration config = ConfigurationManager.OpenExeConfiguration(ConfigurationUserLevel.None);
// change ConnectionString in App.Config for Entity FrameWork Object....
//.....
config.Save();
ConfigurationManager.RefreshSection("connectionStrings");

And now if I create
```
dbContext = new DBFirstContext();
```
It use sourse unchanged connectionString, as it was at starting application. If Close and then restart the application - new dbContext will be created by using modified connectionString.

PS: I don't want to passing new connection string for create new dbContext by using constructor like this:

public DBFirstContext(string sConnectionString)
        : base(sConnectionString)

I need to create dbContext by using default constructor, and that it take a new (changed) connection string from the app.config without restarting the application. Is it possible?

Thank!

Community · Accepted Answer · 2017-05-23 12:32:46Z

3

The App.config is read and parsed only once.

See the answer of "Darin Dimitrov" that was marked as the final answer. Why my changes of AppSettings in App.config is not taken into account in run-time? (Console Application)

I only take credit for Googling for this answer. All other credit should go to Darin.

In short: you're trying to use someting in a way it's not meant to be used. What is the reason you only want to work with the default constructor?

edited May 23, 2017 at 12:32

CommunityBot

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answered Dec 25, 2015 at 21:19

Starceaker

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2 Comments

Владимир В Over a year ago

It is simple, the Application almost is ready, and everywhere were used default constructor for create dbContext, now i need to create option form, where user may custom connection to Data Base...PS:If I restart the application - the configuration file is saved

Starceaker Over a year ago

Based on the feedback what you're trying isn't "correct" so to speak. You should create a function that accepts the parameters (indicating the user selection for that "custom connection") to then create your database connection.

Alexei - check Codidact · Accepted Answer · 2015-12-25 22:18:55Z

0

It is unclear why you need to change app.config or your connection string at runtime, but one way to change the connection string of your context without reconstructing it, is the following:

context.Database.Connection.ConnectionString = "connection string here";

Of course, your connection string must respect the format required by EF, so one way to construct your connection string is:

 String.Format(
@"metadata=res://*/DBFirstContext.csdl|res://*/DBFirstContext.ssdl|res://*/DBFirstContext.msl;provider=System.Data.SqlClient;provider connection string='{0}'", connString);

where connString is a SQL Server connection string

answered Dec 25, 2015 at 22:18

Alexei - check Codidact

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Comments

Владимир В · Accepted Answer · 2015-12-27 08:28:40Z

0

my solution How to use default constructor for create context object by using connectionString from curent App.Config (App.Config were edited at run-time)

        public DBFirstContext()
        : base(System.Configuration.ConfigurationManager.ConnectionStrings["DBFirstContext"].ConnectionString)
    {
    }

answered Dec 27, 2015 at 8:28

Владимир В

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