将IP地址转换为整型数字的PHP方法、Asp方法和MsSQL方法、MySQL方法

首先我们要先了解一下IP地址转换为整型(严格来说应该说是长整型)的原理~

【转换原理】：假设IP为：w.x.y.z，则IP地址转为整型数字的计算公式为：intIP = 256256256w + 256256x + 256y + z

【PHP的互转】：PHP的转换方式比较简单，它内置了两个函数
int ip2long ( string $ip_address )和 string long2ip ( string $proper_address )
可以直接调用使用~

【Asp的互转】：自定义函数如下,
'.-----------------------------------------------------------.
'| describtion: 将IP转换为int型数字 |
'| Authors: abandonship(http://jb51.net) |
'~-----------------------------------------------------------~
Function IP2Num(ByVal strIP)
Dim nIP
Dim nIndex
Dim arrIP
arrIP = Split(strIP, ".", 4)
For nIndex = 0 To 3
If Not nIndex = 3 Then
arrIP(nIndex) = arrIP(nIndex) (256 ^ (3 - nIndex))
End If
nIP = nIP + arrIP(nIndex)
Next
IP2Num = nIP
End Function
'.-----------------------------------------------------------.
'| describtion: 将int型数字转换为IP |
'| Authors: abandonship(http://jb51.net) |
'~-----------------------------------------------------------~
Function Num2IP(ByVal nIP)
Dim strIP
Dim nTemp
Dim nIndex
For nIndex = 3 To 0 Step -1
nTemp = Int(nIP / (256 ^ nIndex))
strIP = strIP & nTemp & "."
nIP = nIP - (nTemp (256 ^ nIndex))
Next
strIP = Left(strIP, Len(strIP) - 1)
Num2IP = strIP
End Function

【MsSQL的互转】：自定义函数如下,
/***

• 将IP转换为int型数字 |
• Code CreateBy abandonship(http://jb51.net) |
  **/
  CREATE FUNCTION [dbo].[ipToInt](
  @strIp varchar(15)
  )RETURNS bigint
  AS
  BEGIN
  declare @nIp bigint
  set @nIp = 0
  select
  @nIp = @nIp + LEFT( @strIp, charindex('.',@strIp+'.')-1)Id
  from(
  select Id = cast(1256256256 as bigint)
  union all select 1256256
  union all select 1*256
  union all select 1
  ) as T
  return (@nIp)
  END

/***

• 将int型数字转换为IP |
• Code CreateBy abandonship(http://jb51.net) |
  **/
  CREATE FUNCTION [dbo].[intToIP](
  @nIp bigint
  )RETURNS varchar(15)
  As
  BEGIN
  declare @strIp varchar(15)
  set @strIp = ''
  select
  @strIp = @strIp +'.'+ cast(@nIp/ID as varchar), @nIp = @nIp%ID
  from(
  select ID = cast(1256256256 as bigint)
  union all select 1256256
  union all select 1256
  union all select 1
  ) as T
  return(stuff(@strIp,1,1,''))
  END

【MySQL的互转】：相对于MsSQL来说MySQL的转换方式比较简单，它和PHP一样也内置了两个函数
IP转为整型: select INET_ATON (IP地址) 和 整型转为IP: select INET_NTOA ( IP的整型数值 )
可以直接调用使用~