uuid

I currently use INT as type for primary key in JavaDB (Apache Derby), but since I'm implementing an distributed system I would like to change the type to java.util.UUID . A few questions about this: What datatype in JavaDB/Derby should I use for UUID? I have seen CHAR(16) FOR BIT DATA been mentioned but I don't know much about it. Is VARCHAR(16) an alternative? How should I use it with JDBC? E.g. in an PreparedStatement , how should I set and get an UUID? If I later would likte to change database to SQL Server, is there a compatible datatype to java.util.UUID? Simply, How should I use UUID

1 ，项目调研 因为需要研究下断点上传的问题。找了很久终于找到一个比较好的项目。 在 GoogleCode 上面，代码弄下来超级不方便，还是配置 hosts 才好，把代码重新上传到了 github 上面。 https://github.com/freewebsys/java-large-file-uploader-demo 效果： 上传中，显示进度，时间，百分比。 点击【 Pause 】暂停，点击【 Resume 】继续。 2 ，代码分析 原始项目： https://code.google.com/p/java-large-file-uploader/ 这个项目最后更新的时间是 2012 年，项目进行了封装使用最简单的方法实现了 http 的断点上传。 因为 html5 里面有读取文件分割文件的类库，所以才可以支持断点上传，所以这个只能在 html5 支持的浏览器上面展示。 同时，在 js 和 java 同时使用 cr32 进行文件块的校验，保证数据上传正确。 代码在使用了最新的 servlet 3.0 的 api ，使用了异步执行，监听等方法。 上传类 UploadServlet @Component("javaLargeFileUploaderServlet") @WebServlet(name = "javaLargeFileUploaderServlet",

In Cassandra, I have the following Column Family: <ColumnFamily CompareWith="TimeUUIDType" Name="Posts"/> I'm trying to insert a record into it as follows using a C++ generated function generated by Thrift: ColumnPath new_col; new_col.__isset.column = true; /* this is required! */ new_col.column_family.assign("Posts"); new_col.super_column.assign(""); new_col.column.assign("1968ec4a-2a73-11df-9aca-00012e27a270"); client.insert("Keyspace1", "somekey", new_col, "Random Value", 1234, ONE); However, I'm getting the following error: "UUIDs must be exactly 16 bytes" I've even tried the Cassandra CLI

We use UUIDs for our primary keys in our db (generated by php, stored in mysql). The problem is that when someone wants to edit something or view their profile, they have this huge, scary, ugly uuid string at the end of the url. (edit?id=.....) Would it be safe (read: still unique) if we only used the first 8 characters, everything before the first hyphen? If it is NOT safe, is there some way to translate it into something else shorter for use in the url that could be translated back into the hex to use as a lookup? I know that I can base64 encode it to bring it down to 22 characters, but is

Underneath the hood JQuery uses a map of "UUIDs" (just a counter it maintains as jQuery.uuid ) to work around the well-known memory leak issues browsers have when you attach a property to a tag in the DOM from Javascript. In lieu of doing so, JQuery uses the $.data(tag, name, value) to store data in a map keyed off of the uuid (a key that can be determined by checking tag[jQuery.expando] ). While $.data() is very useful, there are times you want to map data to tags without dumping that data into one global bucket - you want your own smaller bucket of data that you can, for example, check the

I will try to add some packages related to UUID, i.e, https://www.npmjs.com/package/uuid-generator-ts and https://www.npmjs.com/package/@types/uuid . But I am getting an error, if i install these packages, tell me how generate UUID in angular 6. Nothing to do with Angular itself, you can get uuid from one of the popular npm package such as this: https://www.npmjs.com/package/uuid The code looks like this: import * as uuid from 'uuid'; const myId = uuid.v4(); I know that this might help some users out there. This is what I have done in the past. I have created an Angular ID Service that keeps