Select value from ComboBox and display it's details in textbox

Question

I'm having some problem to display product details from two tables.

I'm using VS 2010, and MS Access Database.

My database table structure are as follow :

• Product (#Product_ID, Category_ID, Product_Name, Product_Cost, Product_Price)

• Category (#Category_ID, Category_Name)

What I want is to display ProductCost, ProductPrice and CategoryName into Textbox when I select ProductName from Combobox. I'm able to display ProductCost & ProductPrice but fail to display CategoryName because I not sure how to make this two table link together.

The code I use to fill Combobox with ProductName is :

Public Sub fillProductCombobox(ByVal sender As Object)
    Dim da As New OleDbDataAdapter
    Dim dt As New DataTable
    Try
        conn.Open()
        da.SelectCommand = New OleDbCommand("SELECT * FROM Product", conn)
        da.Fill(dt)
        sender.DataSource = dt
        sender.DisplayMember = "Product_Name"
        sender.ValueMember = "Product_ID"

        'best method?
        frmAddSalesProduct.txtProductCost.DataBindings.Add("Text", dt, "Product_Cost")
        frmAddSalesProduct.txtPerPrice.DataBindings.Add("Text", dt, "Product_Price")
    Catch ex As Exception
        MsgBox(ex.Message)
    Finally
        conn.Close()
    End Try
End Sub

Then I call the function this way on form load :

fillProductCombobox(ProductComboBox)

This is my how my form look like :

Please guide me how to I display CategoryName as well.

Also is that the way I use to fill Product_Cost and Product_Price the best method?

P/S : For some reason I need to have everything done dynamically

Answer 1

You can use the join query like

 SELECT Product_ID, p.Category_ID, Product_Name, Product_Cost, Product_Price, Category_Name
 FROM Product p
 INNER JOIN Category c ON p.Category_ID = c.Category_ID

So, you will get the category name using this query, just bind the text box as you are binding for others.

I hope it will help you. :)