.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?

Answer 1

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.

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