Can people guess what the next ID will be? How many IDs have been issued? They are usually bits long and look like this in hexadecimal : 30ddc-ee2fdbc9a66 The format is a well-defined sequence of 32 hex digits grouped into chunks of Over a billion years. Files with the same contents will get the same GUID. You can also seed the hash with a unique namespace like your URL. This lets database items created on separate machines be merged later without conflict, and without the need for a central server to manage IDs.
Unique filename for uploaded files. If each version of the file gets its own GUID, you can set a long cache expiration time. Unique name for resources del. A compromise is to generate GUIDs internally and then hand them out. Easily combined: You can merge sets of GUIDs from different data sources with a microscopic chance of conflict.
This is good for security, difficult for debugging. You save time in merging but have to use space to store the large byte GUID. It may not make sense to have a byte GUID keeping track of a 4-byte item in your database. Join k Monthly Readers Enjoy the article?
There's plenty more to help you build a lasting, intuitive understanding of math. Join the newsletter for bonus content and the latest updates. You are saving few bytes but spending much more resources on CPU and time to convert back and forward. Performance will suffer 3. Did you test this approach with sequential GUIDs, are converted values sequential too? Consider how many swear words this can generate Re: Consider how many swear words this can generate Plagiarism geoatif Mar Re: Plagiarism Christiaan van Bergen Mar Hi there, Thank you for this article link.
It actually has a nice solution for a problem stated in one of the other comments. It fixes the special characters that render this Base64 representation potentially unfit for use in urls. That means with intent, right? In that case, no sir. No plagiarism. I just had another source. But maybe you can use my referenced source and harass the author of your suggested article. All fun aside, I've received a couple suggestions of other articles regarding the same subject and solution.
I think an update of this tip with a list of links might be helpful. Re: Plagiarism geoatif Mar No worries. Good to share ideas, overlaps do happen. Removing dash Francis Grignon Mar Francis Grignon. If you remove the dash before applying the base64, would you save 1 or 2 characters? Re: Removing dash Christiaan van Bergen Mar Hi Francis, Good question, but the answer is no.
Even worse, it would mean that will end up with a string that is even longer than the original Guid. Replace " -" , " " ; Console. ToBase64String Encoding. GetBytes guidString ; Console. Method was originally explained on StackOverflow just over 6 years ago The perhaps "original author" of this method is here: Copy Code. Re: Method was originally explained on StackOverflow just over 6 years ago Hi Andrea, Thanks for mentioning this source. The source we found and I did mention was first posted in No problems.
One of things that I have heard a lot in my 25 odd years of software development, is that "Microsoft is very much Bloat-ware". In view of that, much like convergent evolution, there are some of us that come up with the same solutions to a particular problem.
It is bound to happen. I think this solution should be posted in numerous places, as it is highly useful. CodeProject is one of the "goto" places for developers, pardon the pun, and your topic is another useful addition.
For sure, this is a great functionality of C , and I hope I've triggered your curiosity about the hidden aspects of this language. I'm Davide Bellone , a. NET software developer! Let's keep in touch on Twitter! NewGuid ; Console. Before: dbfa9-a2eada8c54 After: dbfa9-a2eada8c Before: fda-4dcb9-a8b7-dfe4a AfterRef: bbc9-a2dd4d3a62f37a. Parse "fcdb-9b1b-ba" ; Console. TryParse "fcdb-9b1b-ba" , out var guid2 ; Console. ToString "D" ; Console.
ToString "N" ; Console. ToString "B" ; Console. ToString "P" ; Console. ToString "X" ;.
0コメント