VB.NET SQL DATAGRID ตันมากครับ เพิ่งเริ่มมาทำงาน เครียดมากๆๆๆๆๆเลยครับ ช่วยหน่อยครับ ขอบคุณมากกกกกกครับ

Private Sub Button4_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button4.Click
        connect()

        Dim num = DataGridView1.RowCount
        num = num - 1
        For i As Integer = 0 To num
            Dim c1 = DataGridView1.Rows(i).Cells(0).Value
            Dim c2 = DataGridView1.Rows(i).Cells(1).Value
            Dim c3 = DataGridView1.Rows(i).Cells(2).Value
            Dim c4 = DataGridView1.Rows(i).Cells(3).Value
            Dim c5 As String = Date.Now.ToString("yyyyMMdd")
            Dim c6 As String = Date.Now.ToString("hhmmss")
            Dim c7 As String = Date.Now.ToString("yyyyMMdd")
            Dim c8 As String = Date.Now.ToString("hhmmss")
            sql = String.Format("Select Count (*) as QTY from Import where Country" = c1 And "[First Date]" = c2 And "[Final Date]" = c3)



            If "QTY" <> 0 Then

                sql = String.Format("Update Import SET Country " = c1, "[First Date]" = c2, "[Final Date] " = c3, "[Exchange Rate]" = c4, "[Update Date]" = c7, "[Update Time]" = c8)
            Else
                sql = String.Format("Insert into import values('{0}','{1}','{2}','{3}','{4}','{5}','{6}','{7}')",
                c1, c2, c3, c4, c5, c6, c7, c8)
            End If
cmd = New SqlCommand(sql, cn)
                cmd.ExecuteNonQuery()
 Next
MsgBox("Saved successfully")
End Sub