Programming VIP

catalogue 1, MySQL PRIMARY KEY Set primary key constraint when creating table Set federated primary key when creating table Delete and modify primary key constraints II. MySQL FOREIGN KEY constraint and UNIQUE constraint Set foreign key constraints and unique constraints when creating tables 3, MySQL CHECK constraint (CHECK) Delete ch ...

1. Basic data type 1.1 numerical type All data in Python are objects, such as well-known int integer objects, float double precision floating-point objects and bool logical objects, which are all single elements. Two examples. Prefix with 0x to create a hexadecimal integer: 0xa5 # Equal to 165 decimal Use e to create floating-point number ...

Use of Vue router router 1, router global configuration Install routing npm install vue-router Create router Usually, for projects created with Vue cli, if we don't import router at first, we need to create it manually. At this time, we create router directory in src directory and index in directory JS, as follows:/** * Router object module ...

JSON:API — Latest Specification (v1.0) Latest specification (v1.0) state This page shows the latest released version of JSON:API, which is currently version 1.0. The new version of JSON:API will always be used, will never be deleted, and only add policies that are backward compatible. Can be in our discuss The district made a supplement. ...

preparation Environmental preparation IDEAMySQL 5.7.31Tomcat 8.5.64Maven 3.6.3 This is my environment. Don't make a big difference in the version. Database preparation CREATE DATABASE `ssmtest`; USE `ssmtest`; DROP TABLE IF EXISTS `user`; CREATE TABLE `user`( `userid` INT(10) NOT NULL AUTO_INCREMENT COMMENT 'user ID', `usern ...

preface It is planned to realize the speech synthesis function, convert text to speech, and support audition and saving functions. After a period of research, it is found that Sogou can be used, with a free quota of 1-2 million words: It is decided to connect with Sogou interface to complete these functions. effect: preparation You c ...

youcans OpenCV learning course - 8 Frequency domain image filtering (Part 2) This series is for Python Xiaobai and explains the actual combat of OpenCV project from scratch. Image filtering is a common image preprocessing operation to suppress the noise of the target image while preserving the detailed features of the image as much as possible ...

catalogue 1, Understanding of class 2, Access qualifier and encapsulation of class 3, Scope and instantiation of class 4, Calculation of object size of class 5, this pointer of class member function 6, Constructor 7, Destructor 8, Copy constructor 9, Operator overloading 10, Implementation of date class Get the number of days per mon ...

1. Why define custom directives After studying the Vue front-end framework, we also know many built-in instructions, such as v-for instruction, v-if instruction, v-bind instruction, v-model instruction and so on. However, because these built-in instructions tend to be instrumental, and sometimes it is necessary to implement specific business l ...

14. Device tree 1. What is a device tree? Device tree is a data structure that describes hardware resources. It transmits hardware resources to the kernel through bootloader, making the description of kernel and hardware resources relatively independent. 2. Origin of device tree To understand why there is a device tree and how it comes from ...