cannot attach file (for database) when hooking up to EF context

greg_skycourt

I am trying to use a typed EF datacontext. I have never been able to create the connection. Here is what I have and what I am doing:

I have my Git repository in C:\Users\gregv\Source\Repo...
I am using the latest EF (not EF Core). My DbContext class is in squashspider.dll.

So I click on Add connection and it brings up the dialog box
I select the second radio button ("Use a typed data context from your own assembly")
I select Entity Framework (DbContext V4/V5/V6)
I hit Next.

I click on Browse to select the squashspider.dll (its in my bin directory)
I leave "via the parameterless constructor" selected.

if I click on Test then it times out.

So I select choose on the "path to the app config file" and select my WebConfig file

Then when I select test, I get the following error (much quicker than the time out)

"An error occurred processing the request

SqlException: Cannot attach the file 'C:\Program files(x86)\LINQPad5\SquashSpiderDB.mdf" as database 'aspnet-SquashSpider-XXX'

of course there is no file at that location. Or is it supposed to be creating a file at that location?

I thought it might be because I am not running LINQPad as administrator and it is trying to create a file in a restricted area.

So I ran it as admin and it did get further. Now I get the error:

"SqlException: A connection was successfully established with the server, but then an error occurred during the login process. (provider: Named Pipes Provider, error: 0 - No process is on the other end of the pipe)

How are you supposed to hook up to your program's specific DbContext?

JoeAlbahari

In your typed datacontext in squashspider.dll, how does it find the correct connection details when you run it in Visual Studio?

robotron

Hi, not the OP, but went through the same steps and have the same problem:

An error occurred processing the request

SqlException: Cannot attach the file 'C:\Program files(x86)\LINQPad5\OrderSystemContext.mdf" as database 'OrderSystemContext'.

Context constructor:

public OrderSystemContext() : base("name=OrderSystemContext")

Web.config:

<connectionStrings>
    <add name="OrderSystemContext" connectionString="Data Source=(localdb)\MSSQLLocalDB; Initial Catalog=OrderSystemContext-20181230131304; Integrated Security=True; MultipleActiveResultSets=True; AttachDbFilename=|DataDirectory|OrderSystemContext-20181230131304.mdf" providerName="System.Data.SqlClient" />
  </connectionStrings>

nescafe

You can paste the connection string in query properties, tab App.config: