I have modified some of the code from the News article section of this book for my own situation. However I have the following problem. I have a stored procedure which returns a number of field values from the database. (eg, field1, field2, field3) but not field4 or field5 as they are not required. However this throws an error in the ArticleProvide class in the method GetArticleFromReader(IDataReader reader, bool readBody). The error line is that of the field not being returned. So for example if field5 is not being returned, the following error is thrown System.IndexOutOfRangeException: field5

If i return all the fields from the database table there is no error.

Any ideas why this is so? And to remind you that I have altered some of the code so I feel the source of the problem may be in that.

Anyone have any ideas for me or want more information or something explained?

Please Help!

you could solve this by giving those properties a default (empty) value ?
if your code expecs a value, you should provide a value.
wat you do is
(reader["field5"] == DBNull.Value ? 0 : (int)reader["field5"])

koen

Thanks very much for your help koen, much appreciated.

However unfortunately it did not change the situation, still have the same error.

Any other ideas?

could you post the SP you have and the GetArticleFromReader code ?

The following is the GetArticleFromReader code.

 protected virtual ArticleDetails GetArticleFromReader(IDataReader reader)
      {
         return GetArticleFromReader(reader, true);
      }
      protected virtual ArticleDetails GetArticleFromReader(IDataReader reader, bool readBody)
      {
            ArticleDetails article = new ArticleDetails(
            (int)reader["ArticleID"],
            (DateTime)reader["AddedDate"],
            reader["AddedBy"].ToString(),
            (int)reader["CategoryID"],
            reader["CategoryTitle"].ToString(),
            reader["Title"].ToString(),
            reader["Abstract"].ToString(),
            null,
            reader["Country"].ToString(),
            reader["State"].ToString(),
            reader["City"].ToString(),
            (reader["ReleaseDate"] == DBNull.Value ? DateTime.Now : (DateTime)reader["ReleaseDate"]),
            (reader["ExpireDate"] == DBNull.Value ? DateTime.MaxValue : (DateTime)reader["ExpireDate"]),
            (bool)reader["Approved"],
            (bool)reader["Listed"],
            (bool)reader["CommentsEnabled"],
            (bool)reader["OnlyForMembers"],
            (int)reader["ViewCount"],
            (int)reader["Votes"],
            (int)reader["TotalRating"]);

         if (readBody)
            article.Body = reader["Body"].ToString();

         return article;
        }

        protected virtual List<ArticleDetails> GetArticleCollectionFromReader(IDataReader reader)
      {
         return GetArticleCollectionFromReader(reader, true);
      }
      protected virtual List<ArticleDetails> GetArticleCollectionFromReader(IDataReader reader, bool readBody)
      {
         List<ArticleDetails> articles = new List<ArticleDetails>();
         while (reader.Read())
            articles.Add(GetArticleFromReader(reader, readBody));
         return articles;
      }

And the following is sample of a stored procedure

ALTER PROCEDURE dbo.tbh_Articles_GetArticleByID
(
   @ArticleID int
)
AS
SET NOCOUNT ON

SELECT tbh_Articles.ArticleID, tbh_Articles.AddedDate, tbh_Articles.AddedBy, tbh_Articles.CategoryID, tbh_Articles.Title, tbh_Articles.Abstract, tbh_Articles.Body,
         tbh_Articles.Country, tbh_Articles.State, tbh_Articles.City, tbh_Articles.ReleaseDate, tbh_Articles.ExpireDate, tbh_Articles.Approved,
         tbh_Articles.Listed, tbh_Articles.CommentsEnabled, tbh_Articles.OnlyForMembers, tbh_Articles.ViewCount, tbh_Articles.Votes, tbh_Articles.TotalRating,
         tbh_Categories.Title AS CategoryTitle
FROM tbh_Articles INNER JOIN
      tbh_Categories ON tbh_Articles.CategoryID = tbh_Categories.CategoryID
   WHERE ArticleID = @ArticleID

Please help!

is the release date or expiredate failing, or is it another field ?

If i leave out any field i get the SystemIndexOutOfRangeExcepetion for that field. So if I used Select * from tbh_Articles INNER JOIN
      tbh_Categories ON tbh_Articles.CategoryID = tbh_Categories.CategoryID
   WHERE ArticleID = @ArticleID

then there would be no problem but If i selected them all bar tbh_Articles.Title for example then I would get a SystemIndexOutOfRange for reader["Title"].ToString().

this architecture expects a reference from the stored procedure for all field described in the class. this is an interface contract between the layers