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How to properly clean after deletion in a navigation collection in a one to many relationship EF 4.3.1

Typically one to many, when I delete as:

var orderEntity = context.Orders.Single(o => o.orderID == entityID);
var baddetail = orderEntity.OrderDetails
                           .Single(od => od.orderDetailID == badOrderDetailID);
orderEntity.OrderDetails.Remove(baddetail);

I get an error:

The operation failed: The relationship could not be changed because one 
or more of the foreign-key properties is non-nullable. When a change is made 
to a relationship, the related foreign-key property is set to a null value. 
If the foreign-key does not support null values, a new relationship must 
be defined, the foreign-key property must be assigned another non-null value, 
or the unrelated object must be deleted.

As a solution, it was proposed to expand DBContext.SaveChanges ()

public override int SaveChanges()
    {

        foreach (OrderDetails od in this.OrderDetails.ToList())
        {
            // Remove OrderDetails without Order.
            if (od.Order == null)
            {
                this.OrderDetail.Remove(od);
            }
        }

        return base.SaveChanges();
    }

But it checks OrderDetails with zero orders, when orderID is not NULL, it seems odd. How to do it right?

EDIT: As an example, this strange deletion happens when you open your Order.OrderDetailsto and DataGrid bindings.

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2 answers

You can just do this:

var orderEntity = context.Orders.Single (o => o.orderID == entityID);
var baddetail = orderEntity.OrderDetails.Single(od => od.orderDetailID == badOrderDetailID);
context.OrderDetails.Remove(baddetail);

. . null FK, , .

+2

OrderDetail Order of OrderDetails. OrderDetail ID null . , FK OrderDetail Order NULL.

var orderEntity = context.Orders.Single(o => o.orderID == entityID);
var baddetail = orderEntity.OrderDetails
                       .Single(od => od.orderDetailID == badOrderDetailID);

context.OrderDetails.Remove(baddetail);
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