Why removed List<Entity> not reflectiong when SubmitChanges() called?

Question

I have this e.g. code:

    var list = (from item in db.Table
        select item).ToList();

[do processing where I modify,add,remove items to the list with a DX GridControl] [Ensure inserted items] [I can see that item(s) are not in the list]

db.SubmitChanges();

Changes not reflecting the DataBase for removed items. What is wrong?

Answer 1

Do you apply your changes with db.SubmitChanges(); method on your data Context? Example from msdn:

var deleteOrderDetails =
    from details in db.OrderDetails
    where details.OrderID == 11000
    select details;

foreach (var detail in deleteOrderDetails)
{
    db.OrderDetails.DeleteOnSubmit(detail);
}

try
{
    db.SubmitChanges();
}
catch (Exception e)
{
    Console.WriteLine(e);
    // Provide for exceptions.
}

Here is the source: http://msdn.microsoft.com/en-us/library/bb386925.aspx

I'm not sure that you can populate the changes from your List to the database if this is what you're trying to achieve.

Answer 2

You cannot modify the list in order to update the database. You have to modify the database entity collections. For example: db.Table.Remove(instance)

Edit: I believe the above syntax is EF4 only. For the original EF, you need to use DeleteOnSubmit, which is a method on your entity container.