Hello everyone, I have datatable that contain data like this public Nullable LogInTime { get ; set ; } public Nullable LogOutTime { get ; set ; } LogInTime = m.Field ( "LogInTime" ), LogOutTime = m.Field ( "LogOutTime" ) And here I have a Linq query for, if LogOutTime is existing null return 'Unknown' message. var logOutDate = (from A in logList select (A.LogOutTime.ToString() ?? "Unknown" ).ToString().Split( new [] { ' ' }, StringSplitOptions.RemoveEmptyEntries)).Distinct(); but getting empty string array in 'logOutDate' object. How can I get Unknown messege if LogOutTime existing null value?

You cannot store a string value in a DateTime datatype. If it is mandatory to give such message like "unknown", you need to create a separate column for displaying such string by using the expression of dataTable. Check below reference http://stackoverflow.com/questions/19325064/how-do-i-use-if-else-or-case-in-datacolumn-expression Hope it helps

Answer

C# - If datetime return null show 'Unknown' message.

Abhilash J A

953

Hello everyone,

I have datatable that contain data like this

public Nullable<DateTime> LogInTime { get; set; }
public Nullable<DateTime> LogOutTime { get; set; }

LogInTime = m.Field<DateTime?>("LogInTime"),
LogOutTime = m.Field<DateTime?>("LogOutTime")

And here I have a Linq query for, if LogOutTime is existing null return 'Unknown' message.

var logOutDate = (from A in logList select (A.LogOutTime.ToString() ?? "Unknown").ToString().Split(new[] { ' ' }, StringSplitOptions.RemoveEmptyEntries)).Distinct();

but getting empty string array in 'logOutDate' object.

How can I get Unknown messege if LogOutTime existing null value?