uniqueidentifier

I want to get from any Unix-like system (if this is possible) a unique id that will be persistent every time my application runs in the same machine. If it is possible, I want to get the same id from Linux or FreeBSD or Solaris, etc... I don't want to generate a new id for each machine, but get an already existent id, and I prefer this id to come from the operating system and I don't prefer to use something like the MAC address. If there is no other option available, I can use MAC in combination with something else, for example the id can be the md5 hash of the combination of the MAC address

Can anyone tell me if there is an equivalent of SCOPE_IDENTITY() when using GUIDs as a primary key in SQL Server? I don't want to create the GUID first and save as a variable as we're using sequential GUIDs as our primary keys. Any idea on what the best way to retrieve the last inserted GUID primary key? You can get the GUID back by using OUTPUT. This works when you're inserting multiple records also. CREATE TABLE dbo.GuidPk ( ColGuid uniqueidentifier NOT NULL DEFAULT NewSequentialID(), Col2 int NOT NULL ) GO DECLARE @op TABLE ( ColGuid uniqueidentifier ) INSERT INTO dbo.GuidPk ( Col2 ) OUTPUT

A table I have no control of the schema for, contains a column defined as varchar(50) which stores uniqueidentifiers in the format 'a89b1acd95016ae6b9c8aabb07da2010' (no hyphens) I want to convert these to uniqueidentifiers in SQL for passing to a .Net Guid. However, the following query lines don't work for me: select cast('a89b1acd95016ae6b9c8aabb07da2010' as uniqueidentifier) select convert(uniqueidentifier, 'a89b1acd95016ae6b9c8aabb07da2010') and result in: Msg 8169, Level 16, State 2, Line 1 Conversion failed when converting from a character string to uniqueidentifier. The same queries

I am making a analytics system, the API call would provide a Unique User ID, but it's not in sequence and too sparse. I need to give each Unique User ID an auto increment id to mark a analytics datapoint in a bitarray/bitset. So the first user encounters would corresponding to the first bit of the bitarray, second user would be the second bit in the bitarray, etc. So is there a solid and fast way to generate incremental Unique User IDs in MongoDB? Konstantin Pribluda You can, but you should not https://web.archive.org/web/20151009224806/http://docs.mongodb.org/manual/tutorial/create-an-auto

I am using this call: Secure.getString(getApplicationContext().getContentResolver(), Secure.ANDROID_ID); To get a UID for the device. I think I am getting the same ID from multiple devices though. Should this be possible? The ID in question is: 9774d56d682e549c and apparently there is an issue with several devices returning this ID http://code.google.com/p/android/issues/list?cursor=10603&updated=10603&ts=1295993403 ninjasense Check into this thread ,. However you should be careful as it's documented as "can change upon factory reset". Use at your own risk, and it can be easily changed on a

So are NFC tags really UNIQUE from each other, at least in their SERIAL NUMBER ? And can we rely on the fact that no 2 NFC tags can have the same serial number? I'm highly skeptical about this as there are (and will be more) NFC tags out there and I don't think anyone is controlling the serials... The reason I'm asking is that I'm developing a key based system using NFC tags. I don't need to write to the tags, I basically just need their serial numbers. But I need them to be truly unique . Also, I would like to know if the serial numbers can be cloned (I know the content of tags can always be

I am creating a new database for a web site using SQL Server 2005 (possibly SQL Server 2008 in the near future). As an application developer, I've seen many databases that use an integer (or bigint , etc.) for an ID field of a table that will be used for relationships. But lately I've also seen databases that use the unique identifier ( GUID ) for an ID field. My question is whether one has an advantage over the other? Will integer fields be faster for querying and joining, etc.? UPDATE: To make it clear, this is for a primary key in the tables. Remus Rusanu GUIDs are problematic as clustered