ip地址进行比较（存储为varbinary） [英] Comparing IPAddress (stored as varbinary)

问题描述

我有我的活动表中的ip地址栏。这被存储作为varbinary（16），使得它可以有效地（moreso不是存储为字符串），并且还支持IPv6。当我保存，我基本上得到（新System.Net.IPAddress（127.0.0.1））的值。GetAddressBytes（）。

I have an IPAddress column on my Activity table. This is stored as a varbinary(16) so that it can be efficient (moreso than storing as a string) and also support IPv6. When I store, I basically get the value of (new System.Net.IPAddress("127.0.0.1")).GetAddressBytes().

我想成为什么能够做的就是寻找与特定字节，例如开头的所有IP地址127 *。我可以很容易地获得该字节，所以只是假设我能得到新的byte [] {127}。

What I want to be able to do is search for all IP addresses that begin with certain bytes, e.g. "127.*". I can easily get the bytes for that, so just assume that I am able to get new byte[] { 127 }.

鉴于这种情况，我怎么能真正写LINQ到SQL查询来获取我我想要的？

Given that, how can I actually write a LINQ to SQL query to get me the data I want?

不幸的是，我没有StartsWith数据，虽然我基本上是想Activity.Where相当于（A => a.IPAddress.StartsWith（新的byte [] {} 127））。

Sadly, I don't have StartsWith, though I essentially want the equivalent of Activity.Where(a => a.IPAddress.StartsWith(new byte[] { 127 })).

推荐答案

如果返回的数据将作为字节数组，为什么不引用数组的第一个字节？听起来像;

If the data is returned as a byte array, why not reference the first byte of the array? Sounds like;

Activity.Where(a => a.IpAddress[0] == 127);

可能是什么你想找的？

might be what your looking for?

您可以在IP地址存储为十六进制的字符串，其中127.0.0.1 =7F000001那么，如果你想找到开头192.168一个IP地址。*您可以使用

You could store the IP address as a hex string, where 127.0.0.1 = "7F000001" then if you want to find an IP address starting with 192.168.* you can use

Activity.Where(a => a.IpAddress.StartsWith("C0A8"));

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