Populate Created and LastModified automagically in EF Core

Question

Looking forward to build a framework, (No repository pattern to working with DbSets directly) to autopopulate Created and last modified automatically, rather than spitting o

Answer 1

One possible solution (the one we're currently using where I work) is to override the SaveChanges() method in the DbContext and add a little bit of code to loop through changed entities setting the values

public override int SaveChanges()
{
    var changedEntriesCopy = ChangeTracker.Entries()
                .Where(e => e.State == EntityState.Added ||
                e.State == EntityState.Modified ||
                e.State == EntityState.Deleted)
                .ToList();
    var saveTime = DateTime.Now;

        foreach (var entityEntry in changedEntriesCopy)
        {
            if (entityEntry.Metadata.FindProperty("Created") != null && entityEntry.Property("Created").CurrentValue == null)
            {
                entityEntry.Property("Created").CurrentValue = saveTime;
            }

            if (entityEntry.Metadata.FindProperty("Updated") != null)
            {
                entityEntry.Property("Updated").CurrentValue = saveTime;
            }
        }
    return base.SaveChanges();
}

Our situation is basically set up similar to that - Created in our situation is nullable so that when a new entity is created the value is null in code up to creation (makes it easy to check if Created has been populated ever).

There may be other solutions, but this was the easiest to get set up for us, and hasnt had any noticeable performance impact