Tag:Double quotation mark

  • Shell learning record


    Special variable $0 file name of the current script $n parameter passed to script or function. N is a number indicating the number of parameters. For example, the first parameter is $1 and the second parameter is $2. $# the number of arguments passed to the script or function. $* all parameters passed to a […]

  • Croncli timer command (golang)


    Timer is a common function when executing tasks. It is too troublesome to configure the timing tasks of the system, so I want to use golang to simply implement a timer command. Through this simple command, you can execute other commands regularly or repeatedly.Gadgets are based on: https://github.com/robfig/cron/ To achieve.Open source Gadgets: https://gitee.com/wangyubin/croncli Timer command […]

  • How to check if the windows system port is occupied


    Sometimes when we use win10 system, we want to check which process occupies the port and how to check it. Let’s share the methods below Method / step The first step is to enter the command in the search box of win10 system task bar. After searching the command prompt, right-click the mouse and select […]

  • Usage instructions for single quotation marks and double quotation marks in PostgreSQL


    In the SQL in PG, single quotation marks are used to identify the actual value, and double quotation marks are used to identify the value existing in the database such as table name or column name. For example, execute a query: select “name” from “students” where “id”=’1′ The advantage of adding quotation marks is that […]

  • #{} how to prevent SQL injection? What is its underlying principle?


    1、 The difference between ${} and #{} in mybatis 1.1 ${}and#{}demonstration Database data: Dao interface: List<User> findByUsername(String username); List<User> findByUsername2(String username); Mapper.xml: <!– Use #{} — > <select id=”findByUsername” parameterType=”java.lang.String” resultType=”com.lscl.entity.User”>     select * from user where username like #{username} </select> <!– When using ${}, note that the value in ${} must be filled in value — > <select id=”findByUsername2″ parameterType=”java.lang.String” resultType=”com.lscl.entity.User”>     select * from user where username like ‘%${value}%’ </select> Execute test code: @Test public void findByUsername() throws Exception {     InputStream in = Resources.getResourceAsStream(“SqlMapConfig.xml”);     SqlSessionFactoryBuilder builder = new SqlSessionFactoryBuilder();     SqlSessionFactory factory = builder.build(in);     //True: Auto […]

  • The fool’s first go program, and then exploded


    The first go program, and then felt its charm Hit the first hello world!, then package main import ‘fmt’ func main() { fmt.Println(‘hello, world!’) } Command run: goearn.go:3:8: illegal rune literal Use Youdao to translate this error as “illegal Rune”, and then carefully check the grammar, whether the words are misspelled, or the case of […]

  • Wechat applet learning


    Because of the need of work, I read the small program document and take notes here. If you want to do well, you must sharpen your tools Official documents of wechat appletOfficial documents IDE download link of wechat appletDeveloper tools download page 1. Project construction After downloading the wechat IDE, open it, create a new […]

  • Learning notes of JSON must know and be able (I)


    What is JSON The full name of JSON is JavaScript object notation, which is a text format (data exchange format) for transferring data between different platforms. There are two common data exchange formats: XML and JSON. We mainly study JSON. Data exchange formats are very important, and developers need to use them to realize data […]

  • Linux: reason why the terminal prompt (prompt) is not effective


    preface Let’s briefly introduce it first,promptWhat the hell is that? As the name suggests, it means prompt. It looks far away from us, but in fact, as long as it is every contactshellWe can see all the children’s shoes. That’s the string of prompts in front of us when we input commands For example: Of […]

  • Zsh Development Guide (Chapter 11 advanced content of variables)


    Reading guide We have talked about the basic usage of the five variables under Zsh (string, array, hash table, integer and floating point number). However, there are some advanced contents in the use of variables, which is very helpful for some special scenarios. Typeset command The typeset command is used to set variables in detail. […]

  • Generate SQL statements through Excel


    Generate SQL statements through Excel Sometimes the business department directly throws over an excel table for us to insert or update into the database. It’s OK to insert. As long as the fields correspond, they can be inserted, but what about updating? Therefore, we need another operation mode to generate the desired SQL statements from […]

  • [JS] JSON in javescript


    JSON, JavaScript object notation, is a data exchange format created by Douglas Crockford inspired by the literal representation of JS.JSON is designed to be a minimalist, lightweight and textual subset of JavaScript. The less consensus is needed to achieve interoperability, the easier it will be to achieve interoperability. The common JSON in our development is […]