guid

原文: [小技巧]EF Core中如何获取上下文中操作过的实体 原文地址： https://www.cnblogs.com/lwqlun/p/10576443.html 作者：Lamond Lu 源代码： https://github.com/lamondlu/EFCoreFindSample 背景介绍 # 当我们在工作单元(UnitOfWork)中使用EF/EF Core的时候，为了要保持事务，一个用户操作只能调用一次SaveChange方法，但是有时候一个用户操作需要调用多个Repository，并且他们操作的实体是关联的。这时候在一个Repository中获取另外一个Repository中添加/修改/删除的实体就变成了一个问题。 问题说明 # 当前我们做一个学生管理系统，学生和班之间是多对多关系，一个学生可以属于多个班， 因此我们创建了如下的EF上下文。 Copy public class TestDbContext : DbContext { public TestDbContext(DbContextOptions<TestDbContext> options) : base(options) { } public DbSet<Student> Students { get; set; } public DbSet<Group> Groups { get; set; }

I need to generate a GUID with XSLT and if needed C#, does anyone know how to best do this? It is to generate unique IDs for HTML items. The XSLT generate-id function returns a string that uniquely identifies a node in the document. Note these warnings from the spec: An implementation is under no obligation to generate the same identifiers each time a document is transformed. There is no guarantee that a generated unique identifier will be distinct from any unique IDs specified in the source document. However, if all you need is to uniquely identify each element in your output, then generate

This is a typical copy-paste error: if some Delphi code containing interface declarations with GUIDs is copy-pasted, Delphi will not complain and compile code which re-uses the same GUID in different places. The "Supports" function works with interfaces based on their GUID, so errors are possible. Is there a 'quality assurance' tool available (Peganza or the Delphi Sonar plugin maybe) which can detect them? If you're on a unix/mac try this - or if you have cygwin on your PC find . -name '*.pas' -exec awk "/\['{.*}'\]/ {print $1}" {} \; | sed 's/ //g' | sort | uniq -d Then to find the

I need to be able to create guids on the fly. Is there a way to do that in MFC? I see how to do it in .net, but we haven't gone there yet. If not, do you have pointers to some code I can use? GUID guid; HRESULT hr = CoCreateGuid(&guid); // Convert the GUID to a string _TUCHAR * guidStr; UuidToString(&guid, &guidStr); The application is responsible for calling RpcStringFree to deallocate the memory allocated for the string returned in the StringUuid parameter. //don't forget to add Rpcrt4.lib to your project CString m_ListID(L"error"); RPC_WSTR guidStr; GUID guid; HRESULT hr = CoCreateGuid(

I need to generate unique folder names, should I use Path.GetRandomFileName or just use Guid.NewGuid ? Guids say they are globally unique, GetRandomFileName does not make such a claim. sidprasher I think both are equally random, the difference being that Path.GetRandomFileName will produce a 8.3 filename (total of 11 characters) so is going to have a smaller set of unique names than those generated by Guid.NewGuid . 来源： https://stackoverflow.com/questions/22625677/should-i-use-path-getrandomfilename-or-use-a-guid

I need to format my GUIDs in the dashed format, all uppercase. I know using myGuid.ToString("D") or String.Format("{0:D}", myGuid) gives the dashed format, but using an uppercase D as opposed to a lower-case d doesn't give me an uppercased GUID like I thought it would. Is there a way to do this without doing anything crazy, or do I just need to call myGuid.ToString().ToUpper() ? do I just need to call myGuid.ToString().ToUpper() Yep. You could go to the effort of creating a custom IFormatProvider, but it doesn't seem worth it here. Note that RFC 4122 , which defines the UUID specification,