What happened to AddOrUpdate in EF 7 / Core?

Question

I\'m writing a seed method using EntityFramework.Core 7.0.0-rc1-final.

What happened to the AddOrUpdate method of DbSet?

Answer 1

I've found a nice solution that allows you specify the property that should match. However, it doesn't take a single entity, but a list in each call. It may give you some hints on how to implement a better version that works like the good-olde one.

https://github.com/aspnet/MusicStore/blob/7787e963dd0b7293ff95b28dcae92407231e0300/samples/MusicStore/Models/SampleData.cs#L48

(Code isn't mine)

Answer 2

I started with Tjaart's answer and modified two things:

1. I'm using the fluent api for key designation so I'm looking for the entity's primary key instead of an attribute on the entity

2. I have change tracking turned on and was getting the error others have mentioned regarding that EF is already tracking it. This does a find on the already tracked entity and copies the values from the incoming entity to it, then updates the original entity

   public TEntity AddOrUpdate(TEntity entity)
   {
       var entityEntry = Context.Entry(entity);
   
       var primaryKeyName = entityEntry.Context.Model.FindEntityType(typeof(TEntity)).FindPrimaryKey().Properties
           .Select(x => x.Name).Single();
   
       var primaryKeyField = entity.GetType().GetProperty(primaryKeyName);
   
       var t = typeof(TEntity);
       if (primaryKeyField == null)
       {
           throw new Exception($"{t.FullName} does not have a primary key specified. Unable to exec AddOrUpdate call.");
       }
       var keyVal = primaryKeyField.GetValue(entity);
       var dbVal = DbSet.Find(keyVal);
   
       if (dbVal != null)
       {
           Context.Entry(dbVal).CurrentValues.SetValues(entity);
           DbSet.Update(dbVal);
   
           entity = dbVal;
       }
       else
       {
           DbSet.Add(entity);
       }
   
       return entity;
   }
   

I've been able to get decent mileage out of it so far without any problems.

I'm using this on EFCore 2.1

Answer 3

You can use this extension method I created to patch our codebase for the migration to EF Core:

   public static void AddOrUpdate<T>(this DbSet<T> dbSet, T data) where T : class
        {
            var t = typeof(T);
            PropertyInfo keyField = null;
            foreach (var propt in t.GetProperties())
            {
                var keyAttr = propt.GetCustomAttribute<KeyAttribute>();
                if (keyAttr != null)
                {
                    keyField = propt;
                    break; // assume no composite keys
                }
            }
            if (keyField == null)
            {
                throw new Exception($"{t.FullName} does not have a KeyAttribute field. Unable to exec AddOrUpdate call.");
            }
            var keyVal = keyField.GetValue(data);
            var dbVal = dbSet.Find(keyVal);
            if (dbVal != null)
            {
                dbSet.Update(data);
                return;
            }
            dbSet.Add(data);
        }

Answer 4

This solution is, I think, a simpler solution to this problem, if assuming a base entity class is a legit option. The simplicity comes from your domain entities implementing DomainEntityBase, which alleviates a lot of the complexities in the other suggested solutions.

public static class DbContextExtensions
{
    public static void AddOrUpdate<T>(this DbSet<T> dbSet, IEnumerable<T> records) 
        where T : DomainEntityBase
    {
        foreach (var data in records)
        {
            var exists = dbSet.AsNoTracking().Any(x => x.Id == data.Id);
            if (exists)
            {
                dbSet.Update(data);
                continue;
            }
            dbSet.Add(data);
        }
    }
}

public class DomainEntityBase
{
    [Key]
    public Guid Id { get; set; }
}

Answer 5

It's waiting to be implemented. See issues #629 & #4526.

Update: according to comments below (unverified) - this feature is finally slated for release in .NET Core 2.1!

Answer 6

I don't understand why people are trying to find the primary key in the other answers. Just pass it when you're calling the method as it's done in EF 6 AddOrUpdate method.

public static TEntity AddOrUpdate<TEntity>(this DbSet<TEntity> dbSet, DbContext context, Func<TEntity, object> identifier, TEntity entity) where TEntity : class
{
    TEntity result = dbSet.Find(identifier.Invoke(entity));
    if (result != null)
    {
        context.Entry(result).CurrentValues.SetValues(entity);
        dbSet.Update(result);
        return result;
    }
    else
    {
        dbSet.Add(entity);
        return entity;
    }
}

and use it later like this:

dbContext.MyModels.AddOrUpdate(dbContext, model => m.Id, new MyModel() { Id = 3 });

Clean and performant.