Question: This is driving me crazy. I am getting error that 

> 
> object doesn't contain definition for DeleteObject.
> 
> 
> 

Here is my line of code that produces an error:

```
ctx.Tanks.DeleteObject(Tank);

```

I tried to reference another object from another `edmx` file that my friend has created and then everything is fine, `DeleteObject` exists. I don't think I miss any references in my project.

And project itself contains edmx file and I used `DBContext` to create POCOs.

Any ideas?

Answer: 
The `DbContext` API defines `DbSet`s not `ObjectSet`s. [DbSet](http://msdn.microsoft.com/en-us/library/gg696460%28v=vs.103%29.aspx) has a `Remove` method not `DeleteObject` method. You need to first decide which API you are going to use. If it the `ObjectContext` or `DbContext`.
```
  [HttpPost]
        public ActionResult Delete(IEnumerable<int> employeeIdsToDelete)
        {
            var lstemployee = _db.StudentEmployees.Where(x => employeeIdsToDelete.Contains(x.Id));
            foreach (var item in lstemployee)
            {
                _db.StudentEmployees.Remove(item);
            }
            _db.SaveChanges();

            return RedirectToAction("Index");
        }

```