Question

I’m trying to use Code First with my local instance of Sql Server 2008 R2. I’ve create a user ‘dev’ and can log in and create databases using Sql Managment Studio. The problem is I keep getting an error message when trying to create a database using DbContext in EntityFramework. Here is the error message:

“A network-related or instance-specific error occurred while
establishing a connection to SQL Server. The server was not found or
was not accessible. Verify that the instance name is correct and that
SQL Server is configured to allow remote connections. SQL Network Interfaces, error: 26 – Error Locating Server/Instance Specified”

The error message I checked my Sql Server and it does allow remote connections.

I’ve abstracted my system with the following code and get the same error:

namespace CodeFirstConsole
{
    public class Program
    {
        static void Main(string[] args)
        {
            var db = new MyContext();
            try { Console.WriteLine(db.Parents.Count()); }
            catch (Exception) { throw; }
            Console.Read();
        }
    }

    internal class MyContext : DbContext
    {
        public DbSet<ParentObject> Parents { get; set; }
        public DbSet<ChildObject> Children { get; set; }

        public MyContext()
        {
            this.Database.Connection.ConnectionString =
                "Data Source=.;Database=ConsoleTest;Initial Catalog=ConsoleTest;User ID=dev;Password=dev;";
        }
    }

    internal class ParentObject
    {
        public int Id { get; set; }
        public string PropertyOne { get; set; }
    }

    internal class ChildObject
    {
        public int Id { get; set; }
        public bool PropertyOne { get; set; }
        public string PropertyTwo { get; set; }

        public virtual ParentObject Parent { get; set; }
    }

    internal class MyInitializer : DropCreateDatabaseAlways<MyContext>
    {

        protected override void Seed(MyContext context)
        {
            context.Parents.Add(new ParentObject() { PropertyOne = "hi" });
            base.Seed(context);
        }
    }
}

Answer 1

I had the same error that drove me nuts for about a day. My situation was I had a large solution with a pre-existing start-up project and I was adding EF to the persistence project.

So the first step was to add the EF dependency. This created an app.config in my persistence project with the correct EF content. Then I went to Enable-Migrations and got the same error in this post. At this point I didn’t think of copying the EF app.config settings to the app.config of the start-up project since I thought I’d have to play around with it before I would eventually run the app.

The problem was resolved when I changed the solution start-up project to the persistence project so I could get EF to find the correct app.config. Or I could have copied the EntityFramwework related section to the app.config of the start-up project.