Try this one. Its working for me in 3tier Architecture Web Application.
"'" + DateTime.Now.ToString() + "'"
Please remember the Single Quotes in the insert Query.
For example:
string Command = @"Insert Into CONFIG_USERS(smallint_empID,smallint_userID,str_username,str_pwd,str_secquestion,str_secanswer,tinyint_roleID,str_phone,str_email,Dt_createdOn,Dt_modifiedOn) values ("
+ u.Employees + ","
+ u.UserID + ",'"
+ u.Username + "','"
+ u.GetPassword() + "','"
+ u.SecQ + "','"
+ u.SecA + "',"
+ u.RoleID + ",'"
+ u.Phone + "','"
+ u.Email + "','"
+ DateTime.Now.ToString() + "','"
+ DateTime.Now.ToString() + "')";
The DateTime
insertion at the end of the line.