null from Server

Question

From my server i stired the server values to datatable for temporary operation.If incase my column has null in my server then its populating an error . String contactNo = (from DataRow dr1 in employeedetail.Rows where (string)dr1[ EmployeeID ] == userid select (string)dr1[ ContactNo ]).FirstOrDefault(); if the column value is null then the error is arising.I dont want to populate error.If value is not null then it will append to my string or else the value will be null.please help me to solve this.

Prasham Sabadra · Answer

Hi Dinesh On null value exception is arising since we are doing (null.FirstOrDefault). I dont know much background of the query but just thought how if you will add one more condition in where clause like String contactNo = (from DataRow dr1 in employeedetail.Rows where (string)dr1[ EmployeeID ] == userid and (string)dr1[ ContactNo ])!= null select (string)dr1[ ContactNo ]).FirstOrDefault();