Hi, here is my code. and it seems that the problem is the format of the output from the sql command. it is not float but a string or what. how can I fix this problem??? many thanks.


SqlConnection myConnection = new SqlConnection("user id=ABC; password=123; Trusted_Connection=yes; Data Source=ABCD\\SQLEXPRESS; Database=MyDb");            
           SqlCommand myCommand = new SqlCommand("SELECT Col1, Col2 FROM MyTable", myConnection);
           myConnection.Open();
           SqlDataReader myReader= null;            
           myReader = myCommand.ExecuteReader();
       while (myReader.Read())
           {
        Chart1.Series["Series1"].Points.AddY(myReader.GetFloat(0));
                Chart1.Series["Series2"].Points.AddY(myReader.GetFloat(1));
      }