SaveChanges() not working in specific use RRS feed

  • Question

  • I have a db first EF 4.0 project. SaveChanges() does not work, although I have no problem getting data via context. This is a Drag - Drop from tree to tree, which has worked before.

    Here are 2 code blocks that read data successfully but do not update / create rows and SaveChanges() fails, never returning to the call; try catch does nothing?

    Create New Object (if doesn't exist)...

    public CategoryGroup VerifyCategoryGroup(int categoryId, int groupId) { var categoryGroup = (from CategoryGroup cg in _db.CategoryGroups where cg.CategoryID == categoryId && cg.GroupCategoryID == groupId select cg).FirstOrDefault(); if (categoryGroup == null) { var newCategoryGroup = new CategoryGroup(); newCategoryGroup.CategoryID = categoryId; newCategoryGroup.GroupCategoryID = groupId; newCategoryGroup.CreatedOn = DateTime.Now; _db.CategoryGroups.AddObject(newCategoryGroup); SaveChanges();
    categoryGroup = newCategoryGroup; } return categoryGroup; }

    Where SaveChanges() is implemented as ...

            public int SaveChanges()
                var changeCount = 0;
                    changeCount = _db.SaveChanges();
                catch (OptimisticConcurrencyException)
                return changeCount;

    Here is an update call ....

            public void UpdateCategoryExtensionData(Category category)
                var priorCategory = (from Category c in _db.Categories
                                     where c.CategoryID == category.CategoryID
                                     select c).FirstOrDefault();
                if(priorCategory != null)
                    priorCategory.ExtensionData = category.ExtensionData;
    I did update from 3.5 to 4 prior to this. Dropping my old edmx and creating a new one. The Entity Linq versions are all 4.0.30319.

    Help me keep my sanity.


    Monday, December 30, 2013 7:59 PM


  • Hello Abbott,

    It is strange that because I made a test that is similar with yours and it worked fine:

      using (DataBaseFirstDBEntities db = new DataBaseFirstDBEntities())
                    Order order = (from o in db.Orders
                                   select o).FirstOrDefault();
                    if (order == null)
                        order = new Order();
                        order.OrderID = 1;
                        order.OrderCode = "1";
                        order.OrderName = "1";

    The difference is that I do not use a global Objectcontext, so I suggest writing the query in a using block to see whether the SaveChange() will work.

    Or if it is possible, you can upload your program to https://skydrive.live.com so that we can download it and test it to figure out why it does not work for you.


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    • Marked as answer by Fred Bao Wednesday, January 8, 2014 5:34 AM
    Tuesday, December 31, 2013 7:25 AM