Object cannot be cast from DBNull to other types in Linq query

Question

I have this linq query that keep returning this error even though I have the DateTime as DBNullable. The trace indicates that the returned values from the database for the insertdate and deletedate are the issue.

This is the error:

at System.DBNull.System.IConvertible.ToDateTime(IFormatProvider provider)

at System.Convert.ToDateTime(Object value)

    public DateTime? insertDate { get; set; }
    public DateTime? deleteDate { get; set; }


    public List<Parameters> fraudResults(DataTable dt)
    {

        var convertedList = (from rw in dt.AsEnumerable()
                             select new Parameters()
                             {
                                 ID = Convert.ToInt32(rw["ID"]),
                                 retailer = Convert.ToString(rw["Retailer"]),
                                 flaggedReason = Convert.ToString(rw["FlaggedReason"]),
                                 insertDate = Convert.ToDateTime(rw["InsertDate"]),
                                 deleteDate = Convert.ToDateTime(rw["DeleteDate"])
                             }).ToList();

        return convertedList;
    }

Any help would be appreciated.

can you change Convert.ToDateTime() to datetime.tryparse () ? — 2174714, Mar 21 '19 at 12:28
You can try like this `rw["InsertDate"] == null ? Datetime.Now : Datetime.Parse(rw["InsertDate"])` — Kunal Mukherjee, Mar 21 '19 at 12:28
c# does not allow a DateTime to be null!!! DateTime as DBNullable is not allowed in Net Library. — jdweng, Mar 21 '19 at 12:29
Possible duplicate of [Handling a DateTime DBNull](https://stackoverflow.com/questions/3978815/handling-a-datetime-dbnull) — Chirag Rupani, Mar 21 '19 at 12:37
Try this: [NotMapped] public DateTime data { get { return DateTime.ParseExact(eventdate, "yyyy-MM-dd'T'HH:mm:ss.fff'Z'", CultureInfo.InvariantCulture); } } — Rogerio Azevedo, Mar 21 '19 at 12:49

score 1 · Answer 1 · answered Mar 21 '19 at 13:10

1

try this

rw["InsertDate"] == DbNull.Value ? null : Convert.ToDateTime(rw["InsertDate"].ToString());

answered Mar 21 '19 at 13:10

N.Siva

66
5

You should also consider just using Dapper : https://github.com/StackExchange/Dapper It takes care of most of these issues and it's lightweight and fast – Peter4499 Mar 21 '19 at 13:39

Object cannot be cast from DBNull to other types in Linq query

1 Answers1