Using arrays with asp.net and VB - asp.net

Question

Sorry, I'm sure this is something that has been covered many times, but I can't find quite what I am after.
I have a single row data table which contains various settings which are used within my web system. I have been toying with turning this into an XML document instead of the single row datatable, would that make more sense?
Anyway, so, given that this is one record, there is a field called "locations," this field contains data as follows:
locationName1,IpAddress|locationName2,IpAddress|etc
The ipAddress is just the first 5 digits of the IP and allows me to ensure that logins to certain elements (admin section managed by staff) can only be accepted when connected from a company computer (ie using our ISP) - this is a largely unnecessary feature, but stops kids I employ logging in at home and stuff!
So, as the user logs in, I can check if the IP is valid by a simple SQL query.
SELECT ips FROM settings WHERE loginLocations LIKE '%" & Left(ipAddress, 5) & " %'
What I need to be able to do now, is get the name of the users location from the dataField array.
I've come up with a few long winded looping procedures, but is there a simple way to analyse
locationName1,IpAddress1|locationName2,IpAddress2|etc
as a string and simply get the locationName where LoginIp = IpAddressX
... or am I going about this in a totally ridiculous way and should turn it into an xml file? (which will then create a whole load of other questions for you about parsing XML!!)

Answer 1

u can split the string in Vb.net and the send it to a query or anything
'Split the string on the "," character
Dim parts As String() = s.Split(New Char() {","c})

Answer 2

In SQL Server, these are the functions of interest in extracting a sub-string:
CHARINDEX
SUBSTRING
LENGTH
You can google the details about them (e.g. CHARINDEX at http://msdn.microsoft.com/en-us/library/ms186323.aspx). With these, you'll need to use computed columns in your query to extract that location name.
If it's not too late, you may want to devise a new way to layout these elements. For instance, instead of:
locationName1,IpAddress1|locationName2,IpAddress2|etc
How about
{IpAddress1,locationName1}{IpAddress2,locationName2}etc
That way you can use CHARINDEX to locate "{" & Left(ipAddress, 5); from that position, locate ","; then from that position locate the closing "}". From there it should be straightforward to use SUBSTRING to get at the locationName. Be forewarned that this will likely be a messy query (probably built from a few sub-queries, one for each position).
In the end, SpectralGhost's idea to just read in the column and do the extraction in VB is probably the way with the least hassle.

Answer 3

I've decided to do it this way, but would appreciate comments on efficiency.
I've split ipAddress and locationName into two database columns, within the one row, and getting the required data by comparing strings as arrays, as per the code below.
For this particular application I'm only dealing with one record, so it's pretty simple. However, further down the line, I need to product a system for monitoring product sales. from an invoices table.
Each invoice record is a row in the database with items in the invoice held similarly, [item1],[item2] etc. There is another column for quantities [qty1],[qty2] etc, prices [price1],[price2], etc. I'll need to be able to search the database for invoices in which an item number occurs (easy SQL WHERE itemList LIKE %[invNO]%) and then compare arrays to get the quantities and individual prices of each item on that invoice. Extracting these rows as arrays and locating the relevant position in these as per the code below, will work fine, but when the whole operation is looping through several hundred or thousand rows, will this become really slow?
ipList, locationList = list as comma separated string from database record field
Dim ipArray As Array = Split(ipList, ",")
Dim locationArray As Array = Split(locationList, ",")
For i = 0 To UBound(ipArray)
If Left(ipArray(i), 5) = Left(ipAddress, 5) Then
arrayPosition = i
itemFound = "True"
Exit For
End If
Next
location = locationArray(arrayPosition)
'loop through ips then get the position and make the location equal to that
If itemFound <> "True" Then
inValidIP = "True"
End If

Answer 4

I strongly advise that you break those our into database columns and each location is a separate row; had it been done that way in the first place, you wouldn't have the problem you have now.
But since you have it in a single row/column, why not bring that back and simply get the value from .NET?
Dim Source As String = "TestLocationA,127.0|TestLocationB,128.0|TestLocationC,129.0"
Dim Test As String = Source
Dim ToFind As String = "127.0"
Test = Test.Substring(0, Test.IndexOf(ToFind & "|") - 1)
Test = Test.Substring(Test.LastIndexOf("|") + 1)
MsgBox(Test)
OR
Public Class Form1
Private IpLocationList As New List(Of IpLocation)
Private IpToFind As String = ""
Private Class IpLocation
Public Name As String
Public IP As String
Public Sub New(ByVal FullLocation As String)
Me.Name = FullLocation.Substring(0, FullLocation.IndexOf(","))
Me.IP = FullLocation.Substring(FullLocation.IndexOf(",") + 1)
End Sub
End Class
Private Function FindIP(ByVal IpLocationItem As IpLocation) As Boolean
If IpLocationItem.IP = IpToFind Then
Return True
Else
Return False
End If
End Function
Private Sub Button1_Click(sender As System.Object, e As System.EventArgs) Handles Button1.Click
Dim Source As String = "TestLocationA,127.0|TestLocationB,128.0|TestLocationC,129.0"
Dim LocationList As New List(Of String)
LocationList.AddRange(Split(Source, "|"))
For Each LocationItem As String In LocationList
IpLocationList.Add(New IpLocation(LocationItem))
Next
IpToFind = "127.0"
Dim result As IpLocation = IpLocationList.Find(AddressOf FindIP)
If result IsNot Nothing Then
MsgBox(result.Name)
End If
End Sub
End Class
enter code here
This has the benefit of loading the array one time and not needing to manually loop through arrays.