Question

EnumType = reader["EnumTypeId"] == DBNull.Value ? EnumType.None : (EnumType)(int)reader["EnumTypeId"];

I thought if reader["EnumTypeId"] is null, it should assign the EnumType.None value, but it is still trying to cast the null value to an int which is obviously causing an exception.

I tried the following and it did not work either:

EnumType = reader["EnumTypeId"] == null ? EnumType.None : (EnumType)(int)reader["EnumTypeId"];

Instead of using Enums, I went ahead and decided to use a nullable int, so now my code is slightly different, but it still does not work with DBNull.Value, null, or GetOrdinal...

intType= reader["intType"] == DBNull.Value ? null : (int?)reader["intType"];

Also, why do I have to do a (int?) cast instead of just a (int) cast?

Answer 1

Don’t use DBNull, just use plain old null.

EnumType = reader["EnumTypeId"] == null ? EnumType.None : (EnumType)(int)reader["EnumTypeId"];

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Edit

The issue could be that the database type of EnumTypeId isn’t an int/Int32. If so, then reading as a string and then parsing should fix the problem.

EnumType? enumVal = null;
if (reader["EnumTypeId"] != null)
{
    int intVal;
    enumVal = (int.TryParse(reader["EnumTypeId"].ToString(), out intVal)) ? (EnumType)intVal : null;
}
EnumType =  ? EnumType.None : (EnumType)(int)reader["EnumTypeId"];