3

Why does this exception occur? Is this a bug?

I'm using Effort, the EF testing library to create an in memory instance of my database and run into this interesting scenario:

  1. Open DbContext1
  2. Add item to Table (do not save)
  3. Close DbContext1
  4. Open DbContext2
  5. Count items in Table

Effort.Exceptions.EffortException : Database has not been initialized.

However, if I perform a count (step 5) also in DbContext1 then the Count in DbContext2 doesn't fail?

Full Code:

public void TestEF()
{
   var factory = new InMemoryMyApplicationDbContextFactory();

   using (var db = factory.CreateDbContext())
   {
      //uncomment this line to prevent exception - why????
      //db.Orders.Count();

      db.Orders.Add(new Order{ Id = Guid.NewGuid() }); 

      // intentionally do not call db.SaveChanges()
   }

   using (var db = factory.CreateDbContext())
   {
      // throws an exception if no read was performed above
      db.Orders.Count();
   }    
}

Full Exception:

Effort.Exceptions.EffortException : Database has not been initialized.

If using CodeFirst try to add the following line:
   context.Database.CreateIfNotExists()
 at System.Data.Entity.Core.EntityClient.Internal.EntityCommandDefinition.ExecuteStoreCommands(EntityCommand entityCommand, CommandBehavior behavior)
 at System.Data.Entity.Core.Objects.Internal.ObjectQueryExecutionPlan.Execute[TResultType](ObjectContext context, ObjectParameterCollection parameterValues)
 at System.Data.Entity.Core.Objects.ObjectContext.ExecuteInTransaction[T](Func`1 func, IDbExecutionStrategy executionStrategy, Boolean startLocalTransaction, Boolean releaseConnectionOnSuccess)
 at System.Data.Entity.Core.Objects.ObjectQuery`1.<>c__DisplayClass7.<GetResults>b__5()
 at System.Data.Entity.Core.Objects.ObjectQuery`1.GetResults(Nullable`1 forMergeOption)
 at System.Data.Entity.Core.Objects.ObjectQuery`1.<System.Collections.Generic.IEnumerable<T>.GetEnumerator>b__0()
 at System.Data.Entity.Internal.LazyEnumerator`1.MoveNext()
 at System.Linq.Enumerable.Single[TSource](IEnumerable`1 source)
Community
  • 1
  • 1
Philip Pittle
  • 11,821
  • 8
  • 59
  • 123

1 Answers1

2

I took the advice mentioned in the exception message and added the following line to my test within the using statement

    db.Database.CreateIfNotExists();

and that worked for me.

Eugenio Miró
  • 2,398
  • 2
  • 28
  • 38