Imports System.Data.SqlClient
Public Class Form1
    Dim cn As SqlConnection
    Dim cmd As SqlCommand
    Dim da As SqlDataAdapter
    Dim dr As SqlDataReader
    Dim ds As New DataSet
 
 
    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        cn = New SqlConnection("Integrated Security=sspi;Initial Catalog =ShalvinPD;Data Source = .\sqlexpress")
        cn.Open()
        da = New SqlDataAdapter("select ProductName,Categoryid ,UnitPrice from Products", cn)
        da.Fill(ds, "products")
        DataGrid1.SetDataBinding(ds, "products")
        fillcombo()
    End Sub
 
 
    Private Sub DataGrid1_CurrentCellChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles DataGrid1.CurrentCellChanged
        Dim x, y, w, h As Integer
        Dim rect As Rectangle
        rect = DataGrid1.GetCurrentCellBounds
        x = rect.X + DataGrid1.Left
        y = rect.Y + DataGrid1.Top
        w = rect.Width
        h = rect.Height
        ComboBox1.SetBounds(x, y, w, h)
        ComboBox1.Visible = True
    End Sub
    Private Sub fillcombo()
        cmd = New SqlCommand("select * from categories", cn)
        dr = cmd.ExecuteReader()
        While dr.Read()
            ComboBox1.Items.Add(dr("categoryName"))
        End While
    End Sub
 
    Private Sub DataGrid1_MouseDown(ByVal sender As Object, ByVal e As System.Windows.Forms.MouseEventArgs) Handles DataGrid1.MouseDown
        MessageBox.Show(e.X.ToString() + " " + e.Y.ToString() + " " + e.Button.ToString())
    End Sub
End Class
 
 
Happy Programming