cant create context in EF6

Question

I have used EF many times, but i cant seem to figure out why this is happening.

I have a solution with 2 projects, one is my common library used in a few other applications that has all my entities and one is my updater console application. In the common library i have my context which looks like so.

public class DalContext : DbContext
{
    public DalContext() : base(ConfigurationManager.ConnectionStrings["DefaultConnection"].ConnectionString)
    {
        Database.SetInitializer(new CreateDatabaseIfNotExists<DalContext>());
    }

    public DbSet<UserAccount> UserAccounts { get; set; }
    public DbSet<GameImport> GameImports { get; set; }

    protected override void OnModelCreating(DbModelBuilder modelBuilder)
    {
        modelBuilder.Conventions.Remove<PluralizingTableNameConvention>();
    }
}

then in my console application i go to create an instance of the context, and i get the error

"Object reference not set to an instance of an object".

I am using a basic using statement to create my context so everything gets disposed properly.

using (var db = new DalContext())
{
    ....
}

i get the error when the using statement is creating the DalContext object.

both applications are using the same version of EF 6.1.3. I was able to do an add-migration just fine. i dunno, i'm stumped.

I have referenced other applications where i have used this and i cannot find any differences as to why this would be happening. I know its going to be something blatantly obvious.

Have you checked that `ConfigurationManager.ConnectionStrings["DefaultConnection"]` is not null? — Rob, Aug 11 '15 at 01:53
Rob was right. Its been a long day, i should be shunned for stepping over a blank connection string. I was looking way deeper into it than i should have. — Barqster7764, Aug 11 '15 at 02:40

score 0 · Answer 1 · edited May 23 '17 at 10:26

In this kind of situation, it's always a good practice to do a binary search debugging. That is, keep on removing stuff until it works. Narrow down the error. Until the bare minimum.

You can try:

Replace this by the actuall connection string: ConfigurationManager.ConnectionStrings["DefaultConnection"].ConnectionString. This is the most likely one. "DefaultConnection" may not be on your web.config/app.config file, that would explain why the same code works for other host projects.
Remove/replace this: Database.SetInitializer(new CreateDatabaseIfNotExists<DalContext>());
Remove/replace this: modelBuilder.Conventions.Remove<PluralizingTableNameConvention>();.

Given the info you have provided, it's impossible for us to help you further.

cant create context in EF6

1 Answers1