Function storage of MySQL high-level statements

1, Database function 1. Mathematical function The records stored in the database often need a series of arithmetic operations, so MySQL supports many mathematical functions. Common mathematical functions Mathematical functiondescribeabs (x)Returns the absolute value of x; The absolute value is always positive, and the absolute value o ...

Posted by UKlee on Fri, 29 Oct 2021 06:54:35 -0700

17-09-02 (public key box *)

The liver lasted eight hours. Finally straightened out the solution of this problem, and found the biggest problem recently. It's bad, it's delicious, but it's worth it. Self summary 1. If you can't do it, don't think about whether multiple cycles work or not. Let's talk about it first. 2. I got 30 points for the first time, but the runni ...

Posted by mezise on Fri, 29 Oct 2021 06:52:21 -0700

http module, node modularization, differences between exports and module.exports, package, npm

http module Concept: a module used to create a web server. Through the http.createServer() method provided by the http module, you can easily turn an ordinary computer into a web server to provide web resource services To create a Web server using the http module, you need to import it first: const http = require('http') Role of http module: 1 ...

Posted by scuff on Fri, 29 Oct 2021 06:48:04 -0700

MySQL full backup and recovery

introduction With the rapid development of office automation and e-commerce, enterprises rely more and more on information system. Database, as the core of information system, plays an important role. Database backup is an important means to recover important data in time and prevent data loss in case of data loss. A reasonable database ...

Posted by Hayce on Fri, 29 Oct 2021 06:46:24 -0700

Golang reflection operation

preface What is reflection? We often use it, and it's a rotten noun. I won't introduce it in detail here In short, there is a variable of unknown type, its type can be obtained through reflection, and its properties and methods can be manipulated Reflection is generally used as a generation tool method. For example, you need a ToString method t ...

Posted by Celauran on Fri, 29 Oct 2021 06:16:16 -0700

Circular statement in Java - array

Statements in Java         1. Sequential structure         2. Select structure         if statement         switch Statements         3. Loop structure - repeat execution          1.for loop -- F ...

Posted by HA7E on Fri, 29 Oct 2021 05:48:30 -0700

JAVA learning 10-29 -- rewriting, super, polymorphism

Method override 1. Override: after a subclass inherits the parent class, it can override the methods in the parent class.2. Application: after rewriting, when a subclass object is created and a method with the same name and parameter in the child parent class is called through the subclass object, the method of overriding the parent class by t ...

Posted by f1nutter on Fri, 29 Oct 2021 05:34:12 -0700

Deep learning_ Perceptron

Deep learning_ Perceptron Reference books: introduction to deep learning_ Theory and Implementation Based on python 1. Perceptron 1.1 principle: receive multiple input signals and output one signal 1.2 diagram: 1.3 diagram: the above figure shows a perceptron receiving two input signals, X1 and X2 are input signals, y are output signals ...

Posted by steveclondon on Fri, 29 Oct 2021 05:33:25 -0700

Acwing 1170. Layout (differential constraint)

Acwing 1170. Layout meaning of the title Cows like to stand close to their friends when waiting in line for feeding. Farmer John has N N N cows, number from 1 1 1 to ...

Posted by JayVee on Fri, 29 Oct 2021 05:15:50 -0700

Vue syntax template

1, Key modifier 1. Style binding 1.1 class binding       v-bind:class="expression"        Type of expression: string, array, object 1.2 style binding       v-bind:style="expression"       Type of expression: string, array, object Specific implementation: <!DOCTYPE html> <html> <head> &l ...

Posted by abhi on Fri, 29 Oct 2021 05:02:34 -0700