Tag:character set

  • Detailed explanation of string and character set in C language


    Detailed explanation of string and character set in C language 1. Character set 2.1. ANSI ANSI is a character set standard issued by the American National Standards Institute. It stipulates that English characters, numeric characters, punctuation marks and control characters are represented in the range of 0x00 ~ 0x7F, which is also known as ASCII […]

  • Analysis of common linux commands


    tr NAME tr – translate or delete characters Characters from standard input can be replaced, compressed and deleted. It can change a group of characters into another group of characters, and is often used to write beautiful single line commands, which is very powerful. SYNOPSIS tr [OPTION]… SET1 [SET2] SET1 Specifies the original character set […]

  • Understanding MySQL character set and comparison rules from root


    character set Abstract description of a character range of coding rules (charset), such as ASCII, GBK, utf8, etc. Encoding: the process of mapping a character to a binary data Decoding: the process of mapping a binary data to a character Comparison rules It is a rule for comparing the size of characters in a character […]

  • SQL — SQL detailed explanation (DDL, DML, DQL, DCL)


    SQL — SQL detailed explanation (DDL, DML, DQL, DCL) Blog description The information involved in this article comes from Internet collation and personal summary, which means personal learning and experience summary. If there is any infringement, please contact me to delete it. Thank you! What is SQL? Structured query language: Structured Query Language SQL general […]

  • Some practical demo and skill analysis of shell


    Demo one Use the loop to create 10 txt files in the / test directory. The file name should have 6 random lowercase letters and a fixed string (_ GG), such as pzjebg_ gg.txt Random string generation /Dev / random relies on system interrupt to generate random string, which can ensure the randomness of data, […]

  • How to unify character set on existing database by MySQL


    preface In the database, part of the data tables and data are Latin1, part of the data tables and data are utf8, and part of the tables, the table structure is utf8 and the data is Latin1. It’s the first time that I’ve been working for more than ten years. Let’s talk about how to […]

  • Chinese coding in QT cross platform programming


    preface in useQt5In the process of development, we encountered some cross platform Chinese code conversion problems, and then conducted a survey. Here is a summary, hoping to help others Character encoding First of all, let’s know about Unicode. Unicode is a character set standard issued by Microsoft and other well-known companies. There are three coding […]

  • How do big factories do SQL tuning?


    Have feelings, have dry goods, wechat search【Third prince Ao Bing】Focus on this different programmer. this paperGitHub https://github.com/JavaFamilyHas been included, there are a large factory interview complete test points, information and my series of articles. preface That day, I was on a lunch break, and the company’s DBA woke me up and said that a large […]

  • Case study of stack SQL optimization: implicit conversion


    Data stack is a cloud native station data platform PAAS. We have an interesting open source project on GitHub and gitee: flinkx. Flinkx is a unified data synchronization tool based on Flink, which can collect both static data and real-time data. It is a global, heterogeneous, batch flow integrated data synchronization engine. If you like, […]

  • Why not use UTF-8 in MySQL?


    I remember last year when I was saving Emoji expression to MySQL, I kept making mistakes and couldn’t import it. And then we found a way — by puttingutf8Change toutf8mb4It’s OK. I didn’t go deep into it. A year later, I read an article that Emoji text takes up four bytes, which usually needs to […]

  • Restore Oracle database DMP file (win system)


    preparation:    1. Check data character set: Generally, when Oracle is installed, ZHS16GBK is selected by default. If there is any change, select userenv (‘language ‘) from dual; statement is used to check the character set used to ensure that the character sets on both sides are consistent. In the case of inconsistency, when importing data, […]

  • Java one year, interview summary


    Xiaoxiao went to the interview again. Today’s interview is summarized as follows First question The database has the following table, and the table structure is as follows Employee number post Organization code employeeID JobTitle OrganizationCode It is required to prepare the staff with more than 10 employees in the DepartmentWrite the corresponding SQL statementanswer select […]