Accepted answer

OK, figured it out

public static IQueryable<IGrouping<string, TSource>> Grouper<TSource>(IQueryable<TSource> source, string field)
            var parameter = Expression.Parameter(typeof(TSource), "x");
            var property = Expression.Property(parameter, field);
            var grouper = Expression.Lambda<Func<TSource, string>>(property, parameter);

            return source.GroupBy(grouper);

Which can be used as (f.Name is the name of the property in TEntity)

Grouper(context.Set<TEntity>(), f.Name)
                                .Where(field => field.Count() > 1)
                                .Select(s => new { Key = s.Key, Count = s.ToList().Count })

Related Articles