Inserting data in Wcf service

Question

Hi, 

In the link below I'm getting error at this line :int result = cmd.ExecuteNonQuery();

UserId isnot included in insert command which is taking null values, which not acceptable,

can u send me updated insert method

 

http://www.c-sharpcorner.com/UploadFile/rohatash/insert-update-and-delete-data-in-gridview-using-wcf-service/