Question

A little tip or help would be very much appreciated, please and thank you.

I have a DataBound ComboBox from my MySql table named "formmaintenance" which has 3 columns namely FormCode, FormName, FormDescription, Combobox DisplayMember is FormCode and ValueMember is FormCode as well, I have 2 TextBoxes named as txtName and txtDesc.

What I would like to happen is when I select an item in Combobox (ex: form101) I want to display the value of FormName of selected item (ex name: Paper) on txtName and FormDescription on txtdesc.

I have yet to know how to start with this, since I’m really new with Vb.Net.

Here is my Code(Updated)

 If conn.State = ConnectionState.Closed Then
            conn.ConnectionString = "Server = localhost; Username= root; Password =; Database =forms"
            Try
                conn.Open()
                MsgBox("Connection Established")
                Dim dt As New DataTable

                Dim sql = "SELECT FormName FROM formma WHERE  FormCode = '" & cmbCode.Text & "';"
                Dim Result As String


                cmd.Connection = conn
                cmd.CommandText = sql
                Result = cmd.ExecuteScalar()
                da.SelectCommand = cmd

                dr = cmd.ExecuteReader()

                If Result IsNot Nothing Then
                    txtName.Text = Result.ToString()

                End If

            Catch ex As MySqlException
                Console.WriteLine("Error: " & ex.ToString())

            End Try
        End If

    End Sub

Answer 1

If I understand your question correctly, here’s the tip.

1- Load data from DB and bind it to the combobox:

     Dim tableFormula as new DataTable("formula");
     using (Dim sqlConn as new SqlConnection("Server = localhost; Username= root; Password =; Database =forms"))
     {
        Dim sqlQuery  as string = "SELECT FormCode, FormName, FormDescription FROM formma;"
        Dim cmd as new SqlCommand(sqlQuery, sqlConn);
        Dim da  as new SqlDataAdapter(cmd); 
        //create dataTable and bind it with dataSet:
        da.Fill(tableFormula);
     }              
     //setting dataSource to comboBox:
     this.cmbCode.DataSource = new BindingSource(tableFormula, null);

2- On SelectedIndex_Changed event handler of cmbCode combobox, set text based on selected item of the combobox.

        if(cmbCode.SelectedItem != null) 
        {
            txtName.Text = ((DataRow)cmbCode.SelectedItem)["FormName"].ToString();
            txtdesc.Text = ((DataRow)cmbCode.SelectedItem)["FormDescription"].ToString();
        }

HTH.