guid

The goal of using a sequential guid is so you can use clustered indexes without the high levels of fragmentation that would normally exist in a clustered index if it was a regular guid, correct? Yes, you are correct. First to clarify, a primary key and clustered index are 2 separate and distinct things, i.e. one is not coupled to the other (PKs can be nonclustered, clustered indexes can be non-PKs). That given, I think you're asking more "Should a Sequential GUID be used as a clustered index". That's a loaded question, but Kimberly Tripp has discussed this probably the best of anyone I've seen

目录 参考文章 REST 常用http动词 WebApi 在 Asp.NetCore 中的实现 创建WebApi项目. 集成Entity Framework Core操作Mysql 安装相关的包(为Xxxx.Infrastructure项目安装) 建立Entity和Context ConfigureService中注入EF服务 迁移数据库 迁移数据库失败, 提示 Unable to create an object of type '<Xxxx>Context'. For the different patterns supported at design time, see https://go.microsoft.com/fwlink/?linkid=851728 数据库迁移结果 为数据库创建种子数据 支持https 支持HSTS 使用SerilLog 安装nuget包 添加代码 自行测试 Asp.NetCore配置文件 默认配置文件 获得配置 自定义一个异常处理,ExceptionHandler 弄一个类,写一个扩展方法处理异常 在Configuration中使用扩展方法 实现数据接口类(Resource),使用AutoMapper在Resource和Entity中映射 为Entity类创建对应的Resource类 使用 AutoMapper

UPDATE Guid.TryParse is available in .NET 4.0 END UPDATE Obviously there is no public GUID.TryParse() in .NET CLR 2.0. So, I was looking into regular expressions [aka googling around to find one] and each time I found one there was a heated argument in the comments section about RegEx A doesn't work, use RegEx B. Then someone would write Regex C yadda yadda So anyway, What I decided to do was this, but I feel bad about it. public static bool IsGuid (string possibleGuid) { try { Guid gid = new Guid(possibleGuid); return true; } catch (Exception ex) { return false; } } Obviously I don't really

Is it possible to declare a constant Guid in C#? I understand that I can declare a static readonly Guid , but is there a syntax that allows me to write const Guid ? No. The const modifier only applies to "primitive" types (bool, int, float, double, long, decimal, short, byte) and strings. Basically anything you can declare as a literal. Declare it as static readonly Guid rather than const Guid public static readonly Guid Users = new Guid("5C60F693-BEF5-E011-A485-80EE7300C695"); and that's that. While you can't seem to do that you can do that to be parsed whenever you need it: const string

I have a service bus, and the only way to transform data is via JavaScript. I need to convert a Guid to a byte array so I can then convert it to Ascii85 and shrink it into a 20 character string for the receiving customer endpoint. Any thoughts would be appreciated. Try this (needs LOTS of tests): var guid = "{12345678-90ab-cdef-fedc-ba0987654321}"; window.alert(guid + " = " + toAscii85(guid)) function toAscii85(guid) { var ascii85 = "" var chars = guid.replace(/\{?(?:(\w+)-?)\}?/g, "$1"); var patterns = ["$4$3$2$1", "$2$1$4$3", "$1$2$3$4", "$1$2$3$4"]; for(var i=0; i < 32; i+=8) { var block =

I have a strongly-typed view which has a DropDownListFor attribute on it. Each item in the dropdown list is represented by a GUID. What I'm after is a way to validate if a user selects an item from the dropdown list. At present i don't see anyway of doing this using Data Annotations. Is there anyway of achieving this using Data Annotations so client and server side validation would work. I'm guessing i need to make a custom method to do this but was wondering if anything already existed. Actually, you can't use Required attribute with GUIDs (without the method I mention below) because they