whn I passed this query through moible application it excute but data not save

string path;
path = System.IO.Path.GetDirectoryName(
System.Reflection.Assembly.GetExecutingAssembly().GetName().CodeBase);
SqlCeConnection con = new SqlCeConnection(@"Data Source=" + path + @"\AppDatabase2.sdf;Persist Security Info=False");
 string Query = "Insert into userlist(usernames,pwd) values('ff','ff')";
 con.Open();
 SqlCeCommand cmd = new SqlCeCommand(Query);
cmd.Connection = con; 

cmd.ExecuteNonQuery();