ProgrammerFail–N Layered Architecture

What is wrong with the following code?

using (SqlDataReader dr = ...)

At the first look, it seems perfect but:

• N layered architecture
• Layers are: DAO –> Factory –> BL –>WebApp

 

And this code with the previous row:

protected void ddlUnits_SelectedIndexChanged(object sender, EventArgs e)
        {
            using (SqlDataReader dr = ...)

!!!FAIL!!!