Looking through the GitHub issues, there is no DbEntityValidationException equivalent in Entity Framework Core. There’s a blog post (linked from issue #9662 on GitHub), that gives a code example for performing the validation logic yourself, included here for completeness: class MyContext : DbContext { public override int SaveChanges() { var entities = from e in … Read more
There is no edmx support in Entity Framework Core. It only supports a code-first approach. The option to add a new Entity Data Model will be added, but it will produce entity class files instead of an edmx file. The tooling development is a little bit behind the framework development currently.
This is 2 years old but I was just in the same situation so it is still relevant. It’s first result on Google for this error. So I can see in your Screenshot that you are not in the standard Windows Visual Studio so I assume you are not on Windows (makes a difference in … Read more
Try accessing PageTitle directly in ThenInclude: using (var dbContext = new BookContext()) { var bookPages = dbContext .Book .Include(x => x.Pages) .ThenInclude(y => y.PageTitle) .SingleOrDefault(x => x.BookId == “some example id”) .Select(x => x.Pages) .Select(x => x.PageTitle) .ToList(); }
Unfortunately EF Core migration s*cks, a lot… I have seen tons of solutions for this but lets do a list of them. So here is what you can do to run and deploy EF migrations without Visual Studio. None of the below is perfect solution all have some caveats: Use EF Core Tools here is … Read more
The reason is clearly stated in the exception. Check the Id on the role object as you receive it on your Edit action and try to lookup that id in the database. The exception message you see states that, it is expecting to find a row with a matching Id of the object you attached, … Read more
By default when you retrieve entities they are tracked and since they are tracked you could just call SaveChanges and not call Update. You can also retrieve entities without tracking them by using .AsNoTracking() calling Update is needed if not tracked already, so if you use AsNoTracking then you do need to use Update before … Read more
Try this public class YourDbContext : DbContext { Ctors() {…} protected override void ConfigureConventions(ModelConfigurationBuilder builder) { builder.Properties<DateOnly>() .HasConversion<DateOnlyConverter>() .HasColumnType(“date”); } } /// <summary> /// Converts <see cref=”DateOnly” /> to <see cref=”DateTime”/> and vice versa. /// </summary> public class DateOnlyConverter : ValueConverter<DateOnly, DateTime> { /// <summary> /// Creates a new instance of this converter. /// </summary> … Read more
I think this is the same problem that I was seeing, and the solution is described in this question: Error while add migration to create database in Entity Framework 6, method not found CoreTypeMappingParameters In a nutshell, what worked was making sure all the entity framework packages were the same version (in my case 6.0.10). … Read more
I implemented an approach similar to this that is covered in this blog post and basically involves creating a service that will use dependency injection to inject the HttpContext (and underlying user information) into a particular context, or however you would prefer to use it. A very basic implementation might look something like this: public … Read more