.NET Core 2 - EF Core Error handling Save changes

Question

I'm used to Entity Framework 6 and my base repository Save() looks like this:

public void Save()
{
    try
    {
        Context.SaveChanges();
    }
    catch (DbEntityValidationException ex)
    {
        // Do stuff
    }
    catch (Exception exception)
    {
        // Do stuff
    }
    else
    {
        throw;
    }
}

DbEntityValidationException is an expected error from Entity Framework if the object save is invalid. Now that I'm on a new .NET Core 2 project. What is the expected entity validation error type in Entity Framework Core?

user_2630078 · Answer

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 ChangeTracker.Entries()
                       where e.State == EntityState.Added
                           || e.State == EntityState.Modified
                       select e.Entity;
        foreach (var entity in entities)
        {
            var validationContext = new ValidationContext(entity);
            Validator.ValidateObject(entity, validationContext);
        }

        return base.SaveChanges();
    }
}

Validator.ValidateObject will throw a ValidationException if validation fails, which you can handle accordingly.

There's a bit more information in the linked issue in case you run into issues with the validation attributes.

Note: The Validator class is located in the System.ComponentModel.DataAnnotations namespace.

.NET Core 2 - EF Core Error handling Save changes

1 Answers