C# Linq OrderBy filtering null or empty values to be last

Question

I try to make my custom orderby extension method, i successfully worked my code but in addition i want to list null or empty or zero values last in result, anyone can help me about that issue ?

Here is my extension method to orderby

    public static IQueryable<T> OrderBy<T>(this IQueryable<T> q, string SortField, bool isAsc)
    {
        //var nullExpr = Expression.Constant(null, typeof(T));
        var param = Expression.Parameter(typeof(T), "p");
        var prop = Expression.Property(param, SortField);
        var exp = Expression.Lambda(prop, param);
        string method = isAsc ? "OrderBy" : "OrderByDescending";
        Type[] types = new Type[] { q.ElementType, exp.Body.Type };
        var mce = Expression.Call(typeof(Queryable), method, types, q.Expression, exp);
        return q.Provider.CreateQuery<T>(mce);
    }

Thanks in advance

Answer 1

The simplest way is to use

OrderBy(e => String.IsNullOrEmpty(e.TeamName)

This doesn't require any extension method or custom IComparer implementation etc.

var entries = repository.Race.Where(e => e.EventId == id)
                      .OrderBy(e => String.IsNullOrEmpty(e.TeamName))
                      .ThenBy(e => e.LastName)
                      .ThenBy(e => e.FirstName);