No connection string named 'MyEntities' could be found in the application config file

I am using entity framework and ASP.NET MVC 4 to build an application

My solution is split into two projects;

A class library that includes my data model (.edmx) file and a few custom interfaces
The 'container' MVC project that references the class library above

My problem is that when I attempt to use the 'MyEntites' DbContext I get the the following error:

No connection string named 'MyEntities' could be found in the application config file.

I guess the problem has something to do with the fact that connection string lies within the app.config of the class library rather than the MVC project.

Does anyone have any suggestions?

Solution 1:

Try copying the connections string to the .config file in the MVC project.

Solution 2:

You are right, this happens because the class library (where the .edmx file) is not your startup / main project.

You'll need to copy the connection string to the main project config file.

Incase your startup / main project does not have a config file (like it was in my Console Application case) just add one (Startup project - Add New Item -> Application Configuration File).

More relevant information can be found here: MetadataException: Unable to load the specified metadata resource

Solution 3:

make sure that you make your project (with the DbContext) as startup

on the project right click and select

Add to the project that is set as startup your connection string in the app.config (or web.config)

Call the command like this

Update-Database -Script -ProjectName '<project name>' -StartupProjectName '<project name>' -ConnectionString 'data source=.;initial catalog=<db name>;integrated security=True;MultipleActiveResultSets=True' -ConnectionProviderName 'System.Data.SqlClient'

Then try again

Solution 4:

You could just pass the connection string to EntityFramework and get on with your life:

public partial class UtilityContext : DbContext
{
    static UtilityContext()
    {
        Database.SetInitializer<UtilityContext>(null);
    }

    public UtilityContext()
        : base("Data Source=SERVER;Initial Catalog=DATABASE;Persist Security Info=True;User ID=USERNAME;Password=PASSWORD;MultipleActiveResultSets=True")
    {
    }

    // DbSet, OnModelCreating, etc...
}

Solution 5:

copy connection string to app.config or web.config file in the project which has set to "Set as StartUp Project" and if in the case of using entity framework in data layer project - please install entity framework nuget in main project.