uuid | 易学教程

Django Rest Framework post primary key uuid or autogenerate

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问题 The following link helped me a lot reference So, by using id = serializers.UUIDField() makes passing an ID required. It will no longer autogenerate if on is missing. I assume at this point that on any serializer I want to be able to POST an id, I need to override the Create method and if no ID is passed in the post data, generate a new uuid there and save the model. Is this correct? OR Is there a way DRF can both allow for and id to be passed in or autogenerate if it is not? EDIT: I tried

前端生成uuid

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//uuid static uuid ( ) { var s = [ ] ; var hexDigits = "0123456789abcdef" ; for ( var i = 0 ; i < 36 ; i ++ ) { s [ i ] = hexDigits . substr ( Math . floor ( Math . random ( ) * 0x10 ) , 1 ) ; } s [ 14 ] = "4" ; // bits 12-15 of the time_hi_and_version field to 0010 s [ 19 ] = hexDigits . substr ( ( s [ 19 ] & 0x3 ) | 0x8 , 1 ) ; // bits 6-7 of the clock_seq_hi_and_reserved to 01 s [ 8 ] = s [ 13 ] = s [ 18 ] = s [ 23 ] = "-" ; var uuid = s . join ( "" ) ; return uuid ; } 来源： CSDN 作者： Boss灬Ming 链接： https://blog.csdn.net/wang993828743/article/details/103973834

How to select minimum UUID with left outer join?

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问题 I'm trying to select a row from a table which: has a minimum UUID is not referenced in another table But I'm having problems when I try to enforce the first constraint. Here's everything working as expected on integers: First, create tables that look like this: t1 +----+---------+ | id | content | +----+---------+ | 1 | a | | 2 | b | | 3 | c | +----+---------+ and t2 +----+---------+ | id | t1_id | +----+---------+ | 1 | 1 | +----+---------+ postgres=# create table t1(id int, content varchar

Convert xs:string to java.util.UUID in jaxb

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问题 In jaxb, how do you convert a string in xsd to java.util.UUID? Is there a built-in data type converter or do I have to create my own custom converter? 回答1: This is much easier to do if you start with Java classes and use JAXB annotations. However, to do this using schema you must use a custom bindings file. Here is an example: Schema: (example.xsd) <?xml version="1.0"?> <xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema" targetNamespace="http://www.example.com" xmlns="http://www.example

Read/Write custom characteristic from BLE device

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问题 I'm trying to interact with a temperature meter BLE device using Android Studio as IDE and Java as programming language. Using an app on my smartphone I discovered the services that this device exposes during its functioning: there were a lot of generic services/characteristic and one custom service. First of all I tried to read the HEALTH THERMOMETER service (UUID = 00001809-0000-1000-8000-00805F9B34FB) TEMPERATURE MEASUREMENT characteristic (UUID = 00002A1C-0000-1000-8000-00805F9B34FB)

Read/Write custom characteristic from BLE device

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How can I convert a UUID to base64?

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问题 I want to take type UUID and output it in a Base64 encoded format, however given the input methods on Base64 and outputs on UUID how to accomplish this doesn't seem obvious. update though not an explicit requirement for my use case, it would be nice to know if the method used uses the raw UUID (the 128 bits that a UUID actually is) of the UUID, as the standard hex encoding does. 回答1: First, convert your UUID to a byte buffer for consumption by a Base64 encoder: ByteBuffer uuidBytes =

Is there a way to retroactively create time/node based UUID in PHP?

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问题 Most time-based (type 1) UUIDs are created using the current time. I'm migrating a MySQL database to cassandra and would like to create timebased UUIDs for archived items. Can someone provide an example of how type-1 UUIDs are created using past time periods? 回答1: All uuids version 1 are a combination of node identifier (MAC address), timestamp and a random seed. Yes its possible. The process is reversible. From RFC4122 about the timestamp part of UUID version 1 (section 4.1.4): "For UUID

mysql and or 查询遇到的坑

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select * from table where m.is_delete = 0 and alow.user_type =3 and alow.is_delete = 0 and ( alow.user_uuid = "08b08c9c-11e3-11ea-965f-07" or alow.user_uuid in (select u.user_uuid FROM ccs_user u LEFT JOIN ccs_dept d on d.dept_uuid = u.dept_uuid where d.parent_uuid = "197128190300.dept_uuid = "1971900") ) 来源： CSDN 作者： stone_tomcat 链接： https://blog.csdn.net/stone_tomcate/article/details/103915532

Data truncated for column 'uuid' at row 1报错可能原因

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解决方法如下：一、检查是否乱码。更改统一的字符类型，比如更改字符类型为utf8；二、如果是 Enum，则可能是添加的字符不在enum类型范围内；三、可能是在alter table更改列设置时，影响原来存入的值，这时可将原值update为需要的类型值或删除这些原值再alter table。四、检查是不是数据类型的长度不一致导致的。这个比较麻烦具体步骤如下： 1、程序中检查日期的范围，当超出时给出提示或其他处理 2、找到mysql 安装目录的 my.ini 3、找到sql-mode=”STRICT_TRANS_TABLES,NO_AUTO_Create_USER,NO_ENGINE_SUBSTITUTION”把其中的 STRICT_TRANS_TABLES,去掉,然后重启mysql。此外在写日期类型时也要注意，mysql 的date类型的支持范围是1000-01-01到9999-12-31，datetime类型的支持范围是1000-01-01 00:00:00 到 9999-12-31 23:59:59。如果尝试把超出范围的值插入数据库中，则会报标题中的错误。采用datetime类型的时候，当日期超出范围时，插入数据库时不报错，但会是一个0000-00-00 或者0000-00-00 00:00:00 扩展资料： MySQL是一个关系型数据库管理系统，由瑞典MySQL AB