VB.NET extracting data from MySql in to a graph

Question

Hi, I have been experimenting with graphs in a windows form using VB.NET

I have had some success as I can now extract data in to my graph.

I created a windows form and dragged a chart on to it using Visual studio 2019. I then placed a button on the form. Inside the button click I have this code.

In my database table I have a column called company and a column called id, the code below successfully extracts the data. But I have now placed a label on my form that labels text shows a specific company name i.e. 'roman.plc'

How can I get my chart to only show data that matches the company name in the label. Because at the moment it shows all company names in the table.

 Try
            Using con As New MySqlConnection("server=Server ip; userid=User; password=MyPassword; database=DatabaseName")
                cmd.Connection = con
                cmd.CommandText = ("select * FROM Registrations ")
                con.Open()
                Dim reader = cmd.ExecuteReader()
                While reader.Read()
                    Chart1.Series("COMPANY_V_ID").Points.AddXY(reader.GetString("Company"), reader.GetInt32("id"))

                End While
                con.Close()
            End Using
        Catch ex As Exception
            MessageBox.Show(ex.Message)
        End Try

Thanks

Answer 1

Hi @nigelsvision nigelsvision ,
I make a test on my side, and you can refer to the following code:

        Using con As New SqlConnection(connString)  
            cmd.Connection = con  
            cmd.CommandText = ("select * FROM Registrations")  
            con.Open()  
            Dim reader = cmd.ExecuteReader()  
            While reader.Read()  
                If reader.GetString("Company").Trim().Equals(Label1.Text) Then  
                    Chart1.Series("COMPANY_V_ID").Points.AddXY(reader.GetString("Company"), reader("id"))  
                End If  
            End While  
        End Using  

Result of my test:

Hope it could be helpful.

Best Regards,
Xingyu Zhao
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