• How do I use guids in c#8


    Translation link:https://www.infoworld.com/art… Guid (global unique identifier) is often used in program development. GUID is like the primary key in the database. It can ensure that some very important information, such as customer data or invoice will not be duplicated or data will be overwritten. If there is no guid, it is difficult to ensure data […]

  • [database] MySQL exercises and answers (educational administration management system)_ MySQL_ 5.7)


    ✨ statement The answer to the exercise is not guaranteed to be completely correct, which is for reference only MySQL:5.7 Recommended software: Navicat premium Learning SQL statements requires diligent practice! ✨ Field description of each table course CId Course serial number, primary key PCId Prerequisite course DId Opening department number, foreign key CName Course name […]

  • Vue mobile license plate selector implementation summary


    Recently, I was working on a small program. There was a vehicle management system inside, which required users to enter license plate information. I didn’t find a Vue component that particularly met my needs on the Internet, so I sorted out the relevant key points and made a Vue component based onVueJSCan be inAppletInternal runningLicense […]

  • Learn the 2D interface of 3D visualization from scratch


    The digital twin visualization scenes built in thingjs are placed in 3D “containers”, which provide 3D and 2D interface display capabilities. The last article analyzed the 3D spatial interface. Now I continue to learn how to connect the 2D interface with the 3D interface. Thingjs has built-in div2d and div3d elements. When creating a 2D […]

  • Introduction and usage of BigDecimal in Java (II)


    1、 BigDecimal formatting Because the format () method of numberformat class can use BigDecimal object as its parameter, BigDecimal can be used to format and control the currency value, percentage value and general value exceeding 16 significant digits. Take the format of currency and percentage with BigDecimal as an example. First, create a BigDecimal object. […]

  • Nine sort specific implementation code


    Statement: the content of this article is only for reference. If there is any mistake, the blogger strongly hopes you to point out. If you are the original blogger of a certain knowledge point, if necessary, you can contact me and add a link. The content of this article will be updated according to the […]

  • Solving Sudoku


    catalogue preface My code Code explanation Running results Solving Sudoku in dance chain summary preface Sudoku this game is very suitable for exercise brain thinking, because the rules are very simple, so it is very suitable for me to write code to crack. So there is this essay.First of all, I want to complete the […]

  • On Kafka’s partition allocation


    order This paper mainly studies the partition allocation of Kafka, mainly the mapping from key to partition, the partition allocation to consumer, and the partition replica allocation to broker / machine. 1. Mapping key to partition In Kafka 0.8, it’s like thiskafka-clients-!/org/apache/kafka/clients/producer/internals/Partitioner.java /** * The default partitioning strategy: * <ul> * <li>If a partition is […]

  • Do you really know about inode in Linux?


    introduction Inode is a very important knowledge point of Linux, understanding it is conducive to our further understanding of Linux system. Today, I happened to see a blog note made by Ruan Yifeng on inode. Here I simply record what I have learned. concept Storage unit: Sector, 512 bytes (equivalent to 0.5kb) A block is […]

  • Front end daily Combat: 170 on the first day of the 1920s, everything has just begun


    Hello everyone, I haven’t published the work “front end daily combat” for some time. Today, the first day of 2020, I will finally start again. I will continue to practice the PBL (project-based learning) learning method, and share my learning notes with you for exchange, discussion and common progress. During this period of unpublished work, […]

  • Hard link and soft link


    introduction Linux foundation is very important, whether it’s work or we usually have to learn, mastering Linux will certainly help you a lot. The following is a brief introduction to LinuxHard linkandSoft connectionIn order for you to better understand my sharing below, you need to master the concept of inode in Linux. If you don’t […]

  • Go and PHP calculate the sum result based on two sets of numbers


    Original link: go letcode, author: San Jin and his meow PHP code Add two numbers This isLeetCodeThe second question is very conventional. The main stem is as follows: Two non empty linked lists are given to represent two non negative integers. Among them, their respective digits are stored in reverse order, and each node can […]