programming

"MySQL must know must know" study notes

0 database script "MySQL Must Know and Know" Reading Notes The database script of this book: mysql must know the official website ####################################### MySQL Crash Course # http://www .forta.com/books/0672327120/ # Example table creation scripts ################################# #### ####################### # Create customers table ##################### ## CREATE TABLE customers ( cust_id int NOT NULL AUTO_INCREMENT, cust_name char ( 50 ) NOT NULL , cust_address char ( 50 ) NUL

Gabrielle

schedule 51 min read

programming

jQuery Ajax

Ajax jQuery Ajax jQuery.ajax() HTTP (Ajax) .ajaxComplete() Ajax Ajax .ajaxError() Ajax Ajax .ajaxSend() Ajax jQuery.ajaxSetup() Ajax .ajaxStart() Ajax Ajax .ajaxStop() Ajax Ajax .ajaxSuccess() Ajax jQuery.get() HTTP GET jQuery.getJSON() HTTP GET JSON jQuery.getScript() HTTP GET JavaScript .load() HTML jQuery.param() URL Ajax jQuery.post() HTTP POST .serialize() .serializeArray() JSON ajax ajax javascript http ajax xmlhttp HTTP ajax javascript ? : : ajax ajax ajax ajax XMLHttpRequest cannot load

Jameson

schedule 4 min read

programming

JavaScript study notes (1) object

An object is an unordered collection of attributes. The so-called attributes are actually our commonly used key-value pair types 1. Create an object (1) Object direct quantity Object direct quantity is composed of several groups of key-value pairs, separated by colons between key and value, separated by commas between key-value pairs, and enclosed in braces for all key-value pairs Among them, the key in the direct quantity of the object can be any string, and the value can be any data type But i

Greyson

schedule 10 min read

programming

Git basics

Git related documentation Two years of squash merge Git features Directly record snapshots, not comparisons of differences (the main differences with other version control systems?) Ensure integrity. The mechanism used by Git to calculate the checksum is called SHA-1 hash (hash) (SHA-1 principle?). This is a string consisting of 40 hexadecimal characters (0-9 and af), calculated based on the content of the file or directory structure in Git. E.g // The string of the git log command is also simil

Emily

schedule 24 min read

programming

|ART

Adaptive Resonance Theory, ART Boston G. A.Carpenter 1976 G. A.Carpenter ART G. A.Carpenter S.Grossberg ATR ART ART ART ART ART ART ART I @[toc] 1. ART ART ART 2. ART I 2.1 2.1.1 ART I C R 3 R G1 G2 2.1.2 C n 3 R G1G_1G1 C 2/3 G1=1G_1 = 1G1 =1 0 2/3 C C=XC=XC=X G1=0G_1=0G1 =0 2/3 C xi = tij ci=xic_i = x_ici =xi ci=0c_i=0ci =0 G1G_1G1 G1G_1G1 C G1G_1G1 C cic_ici xix_ixi tijt_{ij}tij 1 cic_ici 1 0 R C 2.1.3 R R m m m C C R R 1 0 R C R R C 2.1.4 G2G_2G2 XXX 0 X xi 0 G2=0 G2=1 R R0R_0R0 G1=G2G_1=G_

Bradley

schedule 4 min read

programming

Realize the drawing board with canvas-1.0

One, response and analysis During the recent interview, the interviewer asked the canvas to make a window drawing, and I wanted to try if I could draw one out. First of all, let s make a concise version, which can be drawn and erased and can be withdrawn. Then the requirements are set, start analyzing! The first thing I can paint is the function of the brush. I took a look. There are several functions in the canvas, which can be combined to realize the function of the brush. Eraser! Just use cle

Austin

schedule 9 min read

programming

Kaggle Bird call recognition

Contest question Recognize bird calls in soundscape recordings The challenge you face in this competition is to determine which birds are called in the long recording, because the training data is generated in meaningful and different environments. This is the exact problem facing scientists trying to automate remote monitoring of bird populations. Based on the previous game, this competition adds soundscapes from new locations, more bird species, richer metadata about the test set recordings, a

Asher

schedule 15 min read

programming

[Optimization solution] Improved particle swarm optimization algorithm based on tent chaos

2.1  The origin of the idea of particle swarm optimization       The Particle Swarm Optimization (PSO) algorithm is a global random search algorithm based on swarm intelligence proposed by Kennedy and Eberhart, inspired by the results of artificial life research, by simulating the migration and swarming behavior of birds in the foraging process , Various organisms in nature have certain group behaviors, and one of the main research fields of artificial life is to ex

Silas

schedule 6 min read

programming

[Defect Recognition] Classification and measurement of metal surface defects based on matlab GUI SVM [Include Matlab source code 682]

1. Introduction 1.1 Subject content Metal plates are widely used in all aspects of industrial production and production and life. Due to the influence of multiple factors such as equipment and technology involved in the metal plate manufacturing process, the surface of the metal plate is prone to defects of various types and shapes, which affect the wear resistance, corrosion resistance, electromagnetic properties and aesthetics of the metal plate. The properties will have varying degrees of imp

Riley

schedule 13 min read

programming

Regular expression

I used to judge whether the string in the UITextField is in digital form, which is foolish to judge the content inside. The operation is as follows: //Determine whether it is a number if ([self isPureInt:self.lengthTF.text] || [self isPureFloat:self.lengthTF.text]) { //Either an integer or a floating point number [self setShowInfomaton]; }else{ [SVProgressHUD showErrorWithStatus:NSLocaString(@"Please enter the number format")]; } //Determine whether it is an integer -(BOOL)isPureInt:(NSString*)

Lily

schedule 14 min read

programming

Exploitation plan monthly list Top authors list announced in April 2021

hi, friends, hello everyone~ The sixth issue of the monthly list of the digging plan is here~ This issue of the list announced the outstanding creators of the Nuggets community under the three categories of front-end, back-end, and mobile in April 2021, setting an example for the wider community of nuggets, and looking forward to the improvement of Nuggets in the technical field. Well, you can study more technology and output more high-quality content. While helping yourself and others to improv

Levi

schedule 6 min read

programming

TypeScript-advanced types

Welcome to follow WeChat public account: Front-end reading room Advanced type Intersection Types Cross type is to combine multiple types into one type. This allows us to superimpose the existing multiple types together into one type, which contains all the required types of characteristics. For example, Person & Serializable & Loggable are both Person and Serializable and Loggable. That is to say, objects of this type have members of these three types at the same time. We mostly see the

Bentley

schedule 30 min read

programming

Explain in detail the key technologies of Baidu's rich media retrieval and comparison system

Introduction : Baidu rich media retrieval and comparison system is a set of retrieval and content feature comparison technology based on Ann (approximate nearest neighbor), which aims to provide a similar retrieval system for multimedia resources such as images, audios, and videos. Including offline training, database building, online feature extraction and retrieval. At present, Baidu's rich media retrieval and comparison system not only undertakes all Baidu FEED video and image anti-cheating,

Gabrielle

schedule 17 min read

programming

OpenGL_JS-Phongmaterials

lamp vertex shader export let vs_lamp = `#version 300 es layout (location = 0) in vec3 aPos; uniform mat4 model; uniform mat4 view; uniform mat4 projection; void main() { gl_Position = projection * view * model * vec4(aPos, 1.0); }` Copy code lamp fragment shader export let fs_lamp = `#version 300 es precision mediump float; out vec4 FragColor; void main() { FragColor = vec4(1.0); // set alle 4 vector values to 1.0 }` Copy code material vertex shader (lighting model) export let vs_materials = `

Ayden

schedule 7 min read

programming

Personal notes-implementation of static proxy, dynamic proxy and annotation + AOP

Preface I spent two weeks dealing with graduation, dissertation and defense related matters. Today I reviewed the dynamic agency, read some articles, wrote articles for recording, and by the way recorded the aop optimization of the timeline operation records previously done for the project. Static proxy Ready to work First implement an interface IHello and an implementation class HelloImpl /** * @author zhn */ public interface IHello { /** * sayHello */ void sayHello () ; } Copy code /** * @auth

Levi

schedule 10 min read

programming

"JavaScript Advanced Programming" Chapter 25 Client Storage Learning Record

1. Cookie Used to store session information on the client. This specification requires the server to respond to HTTP requests by sendingSet-Cookie HTTP header contains session information HTTP/1.1 200 OK Content-type: text/html Set-Cookie: name=value Other-header: other-header-value Copy code This HTTP response will set a cookie named "name" with a value of "value". Both the name and value are URL-encoded when they are sent. The browser will store these session information, and will send them ba

Calvin

schedule 19 min read

programming

Investigate bytecode instrumentation technology for system monitoring design and implementation

This article is the first signed article in the Nuggets community. Reprinting is prohibited without authorization Author: Small Fu brother blog: bugstack.cn Precipitate, share, grow, so that you and others can gain something! 1. A call from late at night! Yedi, is your online system streaking? Late at night while sleeping on the weekend, I suddenly received a call from the boss urging. "Quickly check WeChat and WeChat, what happened to the system, we didn t know, and we needed feedback from use

Angelina

schedule 30 min read

programming

The evolution of JavaScript modularity

Previous situation review: Self-executing function (IIFE): Role: Execute this function immediately, self-executing function (IIFE), OK -> not easy to read ( Function ( X ) { Console .log (X);}) ( . 3 ); duplicated code Easy-to-read version: ( function ( x ) { return x *x; ))( 3 ); Copy code Closure extension: review: function create_counter ( initial ) { var x = initial || 0 ; //If initial has no value, use the following 0 return { //Object inc : function () { x+= 1 ; return x; } } } var c1 =

Dominic

schedule 13 min read

programming

Handwriting React Fiber rendering logic one

Connect an React Fiber principle The previous article introduced the basic principles of React Fiber. This article will take you to use React Fiber to implement React's first rendering logic. New Project First use create-react-app to create a react application Delete useless files in src and keepindex.jsfile an examinationpackageFile, the react version is17And above, you need to reduce the react version to16 react17 adoptedruntimeMode, no need to introduce at the beginning of the fileReact, Will

Angel

schedule 15 min read

programming

1. 5 1 3(a) 4 7 3(b) 1 3(a) 3(b) 4 5 7 1 3(b) 3(a) 4 5 7 In-place Algorithm 2. 2.1 public class Asserts { public static void test(boolean value) { try { if (!value) throw new Exception(" "); } catch (Exception e) { e.printStackTrace(); } } } 2.2 Integers public class Integers { /** */ public static Integer[] random(int count, int min, int max) { if (count <= 0 || min > max) return null; Integer[] array = new Integer[count]; int delta = max - min + 1; for (int i = 0; i < count; i++) { ar

Jackson

schedule 14 min read