MS Access SQL 查询 IP 地址范围

Question

IP 地址在 Access 数据库中以文本值的形式存储在联结表中，格式为 192.168.0.1 - 192.168.0.254。

连接表，例如区域

Name       IPAddress
Area1      192.168.0.1 - 192.168.0.254
Area2      192.168.1.1 - 192.168.1.254

我需要能够搜索这些范围之间的记录，例如

SELECT * FROM devices WHERE ipaddress = 192.168.0.1 /Returns record Name1

或

SELECT * FROM tablename WHERE ipaddress BETWEEN 192.168.0.1 AND 192.168.0.25 /Returns record Name1,Name2,Name3,etc

Answer 1

一个成功的方法由三个部分组成：

1. 解析IPAddress 列并将其拆分为两个逻辑（文本）列：IPAddressLow 和IPAddressHigh，它们捕获一个区域的 IP 范围。让我们称之为qryAreas：

   select
     [Name]
   , ... as IPAddressLow
   , ... as IPAddressHigh
   from Areas
   

2. 实现一个函数（在 VBA 中，然后您可以从 Access SQL 中调用该函数）来比较 IP 地址。比较器函数可能类似于：

   ' Returns:
   '  -1 if IP1 < IP2
   '   0 if IP1 = IP2
   '   1 if IP1 > IP2
   Function CompareIPAddresses(ip1 As String, ip2 As String) As Integer
     ip1_arr = Split(ip1, ".")
     ip2_arr = Split(ip2, ".")
   
     For i = 0 To 3
       ip1_arr(i) = CLng(ip1_arr(i))
       ip2_arr(i) = CLng(ip2_arr(i))
     Next i
   
     If ip1 = ip2 Then
       retval = 0
     ElseIf ip1_arr(0) < ip2_arr(0) Then
       retval = -1
     ElseIf ip1_arr(0) = ip2_arr(0) And ip1_arr(1) < ip2_arr(1) Then
       retval = -1
     ElseIf ip1_arr(0) = ip2_arr(0) And ip1_arr(1) = ip2_arr(1) And ip1_arr(2) < ip2_arr(2) Then
       retval = -1
     ElseIf ip1_arr(0) = ip2_arr(0) And ip1_arr(1) = ip2_arr(1) And ip1_arr(2) = ip2_arr(2) And ip1_arr(3) < ip2_arr(3) Then
       retval = -1
     Else
       retval = 1
     End If
   
     CompareIPAddresses = retval
   End Function
   

3. 在查询中使用上述函数来确定 IP 地址是否等于某个值或落在某个范围内。例如，如果您有一个地址 192.168.1.100 并想知道它在哪个区域，您可以这样做：

   select [Name]
   from qryAreas
   where CompareIPAddresses(IPAddressLow, '192.168.1.100') in (-1, 0)
   and CompareIPAddresses('192.168.1.100', IPAddressHigh) in (-1, 0)
   

这里的 where 子句与更优雅的 where 192.168.1.100 between IPAddressLow and IPAddressHigh 语法相当笨拙，因为您没有本机 IP 地址数据类型及其相应的运算符 - 所以您自己滚动。

Answer 2

要搜索一系列 IP 地址，您可以使用类似这样的 VBA 小功能

Option Compare Database
Option Explicit

Public Function ZeroPaddedIP(IP As String) As String
    Dim rtn As String, octets() As String, octet As Variant
    rtn = ""
    octets = Split(IP, ".")
    For Each octet In octets
        rtn = rtn & "." & Format(Val(octet), "000")
    Next
    ZeroPaddedIP = Mid(rtn, 2)  ' trim leading "."
End Function

它用前导零填充八位字节

ZeroPaddedIP("192.168.0.1") --> "192.168.000.001"

你的查询可以做类似的事情

SELECT * FROM tablename 
WHERE ZeroPaddedIP(ipaddress) BETWEEN "192.168.000.001" AND "192.168.000.025"

该查询将执行表扫描，因为它不能使用 [ipaddress] 上的任何现有索引。如果性能是一个问题，您可能会考虑以填充形式存储您的 IP 地址（代替或补充正常的未填充格式）。

编辑

对于名为 [NetworkData] 的测试表 ...

ID  IP             Description
--  -------------  -----------
 1  192.168.0.1    router     
 2  192.168.0.2    test server
 3  192.168.0.3    dev server 
 4  192.168.0.102  test client
 5  192.168.0.103  dev client 

...上面显示的 VBA 函数可以在这样的 Access 查询中使用...

SELECT
    IP,
    ZeroPaddedIP(IP) AS PaddedIP
FROM NetworkData

...产生以下结果...

IP             PaddedIP
-------------  ---------------
192.168.0.1    192.168.000.001
192.168.0.2    192.168.000.002
192.168.0.3    192.168.000.003
192.168.0.102  192.168.000.102
192.168.0.103  192.168.000.103

... 但仅当查询是从 Access 本身内部执行时。可以从以下查询中获得相同的结果，但如果查询是从其他应用程序（如 Excel）针对 Access 数据库运行的，则此查询将起作用：

SELECT
    IP,
    Right('000' & Octet1, 3) & '.' & Right('000' & Octet2, 3) & '.' & Right('000' & Octet3, 3) & '.' & Right('000' & Octet4, 3) AS PaddedIP
FROM
    (
        SELECT
            IP,
            Octet1,
            Octet2,
            Left(TheRest2, InStr(TheRest2, '.') - 1) AS Octet3, 
            Mid(TheRest2, InStr(TheRest2, '.') + 1) AS Octet4
        FROM
            (
                SELECT
                    IP,
                    Octet1,
                    Left(TheRest1, InStr(TheRest1, '.') - 1) AS Octet2, 
                    Mid(TheRest1, InStr(TheRest1, '.') + 1) AS theRest2
                FROM
                    (
                        SELECT 
                            IP, 
                            Left(IP, InStr(IP, '.') - 1) AS Octet1, 
                            Mid(IP, InStr(IP, '.') + 1) AS theRest1 
                        FROM NetworkData
                    ) AS q1
            ) AS q2
    ) AS q3

所以，如果您从 Excel（或其他任何地方）查询数据并尝试使用

SELECT * FROM NetworkData 
WHERE IP Between '192.168.0.1' And '192.168.0.25'

你会得到以下不正确的结果

ID  IP             Description
--  -------------  -----------
 1  192.168.0.1    router     
 2  192.168.0.2    test server
 4  192.168.0.102  test client
 5  192.168.0.103  dev client 

如果你使用过

SELECT NetworkData.* 
FROM
    NetworkData
    INNER JOIN
    (
        SELECT
            IP,
            Right('000' & Octet1, 3) & '.' & Right('000' & Octet2, 3) & '.' & Right('000' & Octet3, 3) & '.' & Right('000' & Octet4, 3) AS PaddedIP
        FROM
            (
                SELECT
                    IP,
                    Octet1,
                    Octet2,
                    Left(TheRest2, InStr(TheRest2, '.') - 1) AS Octet3, 
                    Mid(TheRest2, InStr(TheRest2, '.') + 1) AS Octet4
                FROM
                    (
                        SELECT
                            IP,
                            Octet1,
                            Left(TheRest1, InStr(TheRest1, '.') - 1) AS Octet2, 
                            Mid(TheRest1, InStr(TheRest1, '.') + 1) AS theRest2
                        FROM
                            (
                                SELECT 
                                    IP, 
                                    Left(IP, InStr(IP, '.') - 1) AS Octet1, 
                                    Mid(IP, InStr(IP, '.') + 1) AS theRest1 
                                FROM NetworkData
                            ) AS q1
                    ) AS q2
            ) AS q3
    ) AS q4
        ON q4.IP = NetworkData.IP
WHERE q4.PaddedIP Between '192.168.000.001' And '192.168.000.025'

您将收到以下正确结果

ID  IP           Description
--  -----------  -----------
 1  192.168.0.1  router     
 2  192.168.0.2  test server
 3  192.168.0.3  dev server