Question

I have a linq query which is not ordered the way I would like.

The Query:

return (from obj in context.table_orders
    orderby obj.order_no
    select obj.order_no.ToString() + '-' + obj.order_description).ToList<string>();

What happens is that my records are ordered alphabeticaly, is there a Linq keyword I can use so my records are ordered correctly (so order 30 comes before order 100)?

I want the result to be a list of string since this is used to populate a ComboBox.

Also some of the ‘order_no’ in the DB are like ‘2.10’ and ‘9.1.1’.

Answer 1

Since nobody came up with a custom orderby function translatable into SQL, I went for the IComparer function like so:

    public class OrderComparer<T> : IComparer<string>
    {
        #region IComparer<string> Members

        public int Compare(string x, string y)
        {
            return GetOrderableValue(x.Split('-').First()).CompareTo(GetOrderableValue(y.Split('-').First()));
        }
        #endregion

        private int GetOrderableValue(string value)
        {
            string[] splitValue = value.Split('.');
            int orderableValue = 0;
            if (splitValue.Length.Equals(1))
                orderableValue = int.Parse(splitValue[0]) * 1000;
            else if (splitValue.Length.Equals(2))
                orderableValue = int.Parse(splitValue[0]) * 1000 + int.Parse(splitValue[1]) * 100;
            else if (splitValue.Length.Equals(3))
                orderableValue = int.Parse(splitValue[0]) * 1000 + int.Parse(splitValue[1]) * 100 + int.Parse(splitValue[2]) * 10;
            else
                orderableValue = int.Parse(splitValue[0]) * 1000 + int.Parse(splitValue[1]) * 100 + int.Parse(splitValue[2]) * 10 + int.Parse(splitValue[3]);

            return orderableValue;
        }
    }

The values have a maximum of 4 levels.
Anyone has a recommandation?