Question

IP地址作为文本值存储在Access数据库中，格式为192.168.0.1 - 192.168.0.254在联结表中。

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

要搜索一系列IP地址，您可以使用像这样的小VBA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，所以

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

您的查询可以执行类似

的操作

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，因为它无法使用[ipaddress]上的任何现有索引。如果性能有问题，您可以考虑以填充形式存储您的IP地址（代替正常的非填充格式，或者除了正常的非填充格式之外）。

修改

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

...但仅限于从Access本身执行查询。可以从以下查询获得相同的结果，但是如果从其他应用程序（如Excel）对Access数据库运行查询，则此结果将起作用：

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

因此，如果您从Excel（或任何地方）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

而如果您使用

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

Answer 2

成功的方法将由三部分组成：

解析IPAddress列并将其拆分为两个逻辑（文本）列：IPAddressLow和IPAddressHigh，用于捕获区域的IP范围。我们称之为qryAreas：
```
select
  [Name]
, ... as IPAddressLow
, ... as IPAddressHigh
from Areas
```

实现一个函数（在VBA中，然后可以从Access SQL中调用）来对IP地址进行比较。比较器功能可能类似于：

' 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

在查询中使用上述函数来确定IP地址是否等于某个值或是否在某个范围内。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子句是更优雅的where 192.168.1.100 between IPAddressLow and IPAddressHigh语法的笨重等价物，因为你没有本机IP地址数据类型及其相应的运算符 - 所以你滚动你的自己的。

MS Access SQL查询IP地址范围

2 个答案: