โค้ดนี้จะเช็คข้อมูลซ้ำได้ยังไงครับ VB.NET + MySQL

Dim intNumrow As Integer
        Dim strsql As String
        strsql = "Select Count(*) from GoodsCheck Where goodsID='" & Me.txtgoodsid.Text & "' And room='" & Me.cbbroom.Text & "'"
        conn.Open()
        cm = New SqlCommand(strsql, conn)
        intNumrow = cm.ExecuteScalar()
        conn.Close()

        If intNumrow > 0 Then

            Dim strcon3 As String
            strcon3 = "Update GoodsCheck Set sumAmount='" & i2.ToString & "' Where goodsID='" & Me.txtgoodsid.Text & "' And room='" & Me.cbbroom.Text & "'"
            conn.Open()
            cm = conn.CreateCommand()
            With cm
                .CommandText = strcon3
                .CommandType = CommandType.Text
                .ExecuteNonQuery()
            End With
            conn.Close()

        Else

            Dim strcon4 As String
            strcon4 = "Insert into GoodsCheck (goodsID,room,sumAmount) Values ('" & txtgoodsid.Text & "' , '" & cbbroom.Text & "', '" & txtOutamount.Text & "')"
            conn.Open()
            cm = conn.CreateCommand()
            With cm
                .CommandText = strcon4
                .CommandType = CommandType.Text
                .ExecuteNonQuery()
            End With
            conn.Close()

        End If