Cannot Cast Dbnull.value To Type 'system.datetime'. Please Use A Nullable Type

This is my code var finalResults = (from r in results.AsEnumerable() where r.Field('PrintTime') is DBNull where PrintTime is a column in my Sql

Solution 1:

DataRow.Field supports nullable types, so use DateTime? instead of DateTime:

var finalResults = from r in results.AsEnumerable()
                   let printTime = r.Field<DateTime?>("PrintTime")
                   where !printTime.HasValue
                   select r;