Generic sorting method. #EF, #LINQ.

QueryableExt.cs

public static class QueryableExt
{
    public static IOrderedQueryable<T> OrderBy<T>(IQueryable<T> source, string propertyName, bool descending, bool anotherLevel = false)
    {
        ParameterExpression param = Expression.Parameter(typeof(T), string.Empty); // I don't care about some naming
        MemberExpression property = Expression.PropertyOrField(param, propertyName);
        LambdaExpression sort = Expression.Lambda(property, param);

        MethodCallExpression call = Expression.Call(
            typeof(Queryable),
            (!anotherLevel ? "OrderBy" : "ThenBy") + (descending ? "Descending" : string.Empty),
            new[] { typeof(T), property.Type },
            source.Expression,
            Expression.Quote(sort));

        return (IOrderedQueryable<T>)source.Provider.CreateQuery<T>(call);
    }

    public static IOrderedQueryable<T> OrderBy<T>(this IQueryable<T> source, string propertyName)
    {
        return OrderBy(source, propertyName, false, false);
    }

    public static IOrderedQueryable<T> OrderByDescending<T>(this IQueryable<T> source, string propertyName)
    {
        return OrderBy(source, propertyName, true, false);
    }

    public static IOrderedQueryable<T> ThenBy<T>(this IOrderedQueryable<T> source, string propertyName)
    {
        return OrderBy(source, propertyName, false, true);
    }

    public static IOrderedQueryable<T> ThenByDescending<T>(this IOrderedQueryable<T> source, string propertyName)
    {
        return OrderBy(source, propertyName, true, true);
    }
}