This is a great question. First of all, here are a couple of workarounds that come to mind (they all require changes to the query): First workaround This one maybe a bit obvious and unfortunately not generally applicable: If the selection of items you would need to pass over to Enumerable.Contains already exists in a … Read more
You need to add a blank “merge” migration that will reset the snapshot of the latest migration in the .resx file. Do this using the IgnoreChanges switch: Add-Migration <migration name> -IgnoreChanges See here for an explanation
As mentioned by @anon you can’t attach model once you loaded the entity with the same key. The changes must be applied to attached entity. Instead of this: db.Entry(model).State = EntityState.Modified; use this: db.Entry(v).CurrentValues.SetValues(model);
First off, with 11k question views at the time of this writing, I’m a little surprised by the lack of answers and with all due respect, the quality of the answers, given a fairly straightforward question. So, now that I’ve vented a little bit, I’d like to address this question(s) because I think that it … Read more
1) First you need to generate EDMX model using your database. To do that you should add new item to your project: Select ADO.NET Entity Data Model from the Templates list. On the Choose Model Contents page, select the Generate from Database option and click Next. Choose your database. On the Choose Your Database Objects … Read more
In EF6 a faster way to do the operation is… context.Children.RemoveRange(parent.Children)
In Entity Framework 6 the delete action is Remove. Here is an example Customer customer = new Customer () { Id = id }; context.Customers.Attach(customer); context.Customers.Remove(customer); context.SaveChanges();
While you are in debug mode within the catch {…} block open up the “QuickWatch” window (ctrl+alt+q) and paste in there: ((System.Data.Entity.Validation.DbEntityValidationException)ex).EntityValidationErrors This will allow you to drill down into the ValidationErrors tree. It’s the easiest way I’ve found to get instant insight into these errors. For Visual 2012+ users who care only about the … Read more
In case you have base class or interface defining the IsActive property, you could use the approach from Filter all queries (trying to achieve soft delete). Otherwise you could iterate entity types, and for each type having bool IsActive property build dynamically filter expression using Expression class methods: foreach (var entityType in modelBuilder.Model.GetEntityTypes()) { var … Read more
For the latest EF Core version (should work for 3.0 also, for earlier versions expression replacement should be handled manually, see ReplacingExpressionVisitor call) you can automate it using some reflection (minimal amount of it), expression trees and IMutableModel.GetEntityTypes in your OnModelCreating method. Something like this should work: // define your filter expression tree Expression<Func<BaseModel, bool>> … Read more