C#

Public Function QuadKeyToBBox(quadKey As String) As String
    Dim TILE_HEIGHT As Integer = 256
    Dim TILE_WIDTH As Integer = 256
    Dim zoom As Integer = quadKey.Length
    Dim x As Integer = 0
    Dim y As Integer = 0

    For i As Integer = zoom To 1 Step -1
        Dim mask As Integer = 1 << (i - 1)
        Select Case quadKey(zoom - i)
            Case "0"C
                Exit Select
            Case "1"C
                x = x Or mask
                Exit Select
            Case "2"C
                y = y Or mask
                Exit Select
            Case "3"C
                x = x Or mask
                y = y Or mask
                Exit Select
            Case Else
                Throw New ArgumentException("Invalid QuadKey digit sequence.")
        End Select
    Next

    Dim W As Double = CSng(x * TILE_WIDTH) * 360 / CSng(TILE_WIDTH * Math.Pow(2, zoom)) - 180
    Dim N As Double = CSng(Math.Asin((Math.Exp((0.5 - ((y * TILE_HEIGHT) / (TILE_HEIGHT)) / Math.Pow(2, zoom)) * 4 * Math.PI) - 1) / (Math.Exp((0.5 - ((y * TILE_HEIGHT) / 256) / Math.Pow(2, zoom)) * 4 * Math.PI) + 1))) * 180 / CSng(Math.PI)
    Dim E As Double = CSng((x + 1) * TILE_WIDTH) * 360 / CSng(TILE_WIDTH * Math.Pow(2, zoom)) - 180
    Dim S__1 As Double = CSng(Math.Asin((Math.Exp((0.5 - (((y + 1) * TILE_HEIGHT) / (TILE_HEIGHT)) / Math.Pow(2, zoom)) * 4 * Math.PI) - 1) / (Math.Exp((0.5 - (((y + 1) * TILE_HEIGHT) / 256) / Math.Pow(2, zoom)) * 4 * Math.PI) + 1))) * 180 / CSng(Math.PI)
    Dim bounds As Double() = New Double() {W, S__1, E, N}

    Return String.Join(",", Array.ConvertAll(bounds, Function(s__2) s__2.ToString()))
End Function

MDL=>Moshu wrote:

Better use access in that case.

MDL=>Moshu wrote:

Many pros for using it as a single user or local db vs sql.

Henry Minute wrote:

non standard SQL