This is an old question, but I had to solve it in order for a system I was working on to be backward compatible. The exact requirement was for a client-generated identifier that would be written to the database and stored in a 20-character unique column. It never got shown to the user and was … Read more
You can use the SYS_GUID() function to generate a GUID in your insert statement: insert into mytable (guid_col, data) values (sys_guid(), ‘xxx’); The preferred datatype for storing GUIDs is RAW(16). As Gopinath answer: select sys_guid() from dual union all select sys_guid() from dual union all select sys_guid() from dual You get 88FDC68C75DDF955E040449808B55601 88FDC68C75DEF955E040449808B55601 88FDC68C75DFF955E040449808B55601 As … Read more
Use one file per component – this avoids all sorts of problems (except .NET assemblies spanning multiple files). See the following thread: One file per component or several files per component? Wix is a great framework for creating installers, but it has a steep learning curve. I strongly recommend you read a few sections of … Read more
Well, as noted above I found out how to get dbcc_name to populate correctly. I found that this was the easiest way to get the device name: private static string GetDeviceName(DEV_BROADCAST_DEVICEINTERFACE dvi) { string[] Parts = dvi.dbcc_name.Split(‘#’); if (Parts.Length >= 3) { string DevType = Parts[0].Substring(Parts[0].IndexOf(@”?\”) + 2); string DeviceInstanceId = Parts[1]; string DeviceUniqueID = … Read more
I’ve noticed that some methods such as Supports (to determine if a class conforms to a specific interface) require that you define a GUID before you can use them. This page confirms it with the following information: Note: The SysUtils unit provides an overloaded function called Supports that returns true or false when class types … Read more
Here is some stuff from Wikipedia (original source): V1 GUIDs which contain a MAC address and time can be identified by the digit “1” in the first position of the third group of digits, for example {2f1e4fc0-81fd-11da-9156-00036a0f876a}. In my understanding, they don’t really hide it. V4 GUIDs use the later algorithm, which is a pseudo-random … Read more
Product/@Id=”*” randomly generates a new GUID, which is sufficient for product codes. Component/@Guid=”*” calculates a GUID that stays the same as long as your target path stays the same, which is necessary to comply with component rules.
If you have a very large table, then searching against values that aren’t indexed can be extremely slow. In MySQL terms this kind of query ends up being a “table scan” which is a way of saying it must test against each row in the table sequentially. This is obviously not the best way to … Read more
It appears that MS are storing the five parts in a structure. The first 4 parts are either 2 or 4 bytes long and are therefore probably stored as a native type (ie. WORD and DWORD) in little endian format. The last part is 6 bytes long and it therefore handled differently (probably an array). … Read more
If you look at the values involved (in pairs) of hex digits you can see that the last 7 bytes are the same in both cases, but the first 9 are switched around a bit. Going from your example, but rewriting each pair in the .NET as 00, 11, 22 etc and switching the relevant … Read more