JOIN of MySQL (1): Usage

JOIN, like the English word "join", connects two tables, roughly divided into internal connection, external connection, right connection, left connection and natural connection. This description first throws out a rotten graph and then inserts the test data. CREATE TABLE t_blog( id INT PRIMARY KEY AUTO_INCREMENT, ...

Posted by haddydaddy on Mon, 27 May 2019 00:22:53 +0200

node.js command line tutorial

node command line tutorial This article first introduces the native node.js for command line interaction, understanding the native api, and then implementing a complete interactive command line tool using commander.js and inquirer.js.Project Address process The process object is a global variable that provides information about and controls the ...

Posted by seatoomol7 on Sun, 26 May 2019 22:57:54 +0200

About javascript object-oriented (for beginners)

1. About Objects 1. Original mode var person = new Object(); person.name="Jack"; person.age=29; person.message=function () { alert(this.name+" is "+this.age); }; alert(person.name);//Jack person.message();//Jack is 29 2. Create Objects There are three modes: (1) Factory mode: function Person(name,age,hobby){ var a= new Object ...

Posted by DJTim666 on Sun, 26 May 2019 20:29:15 +0200

tab toggle between different solutions

tab switch, the front-end gods are familiar with, however, because there are too many occasions, so you may not care about it.I don't know if you want to comb your logic and write it once or use the existing templates or your own libraries when you encounter this kind of situation. Today I summarize my experience and optimize the following poin ...

Posted by DK_Sun on Sun, 26 May 2019 18:32:45 +0200

Solving Ajax Cross-domain Problem-JSONP Principle Analysis

Solving Ajax Cross-domain Problem-JSONP Principle Analysis Why are there cross-domain problems? - Because there are homologous strategies Homology is a security policy for browsers. Homology refers to the protocol in the request URL address. Domain names and ports are the same, as long as one of them is different, it is cros ...

Posted by shimano55 on Sat, 25 May 2019 01:19:08 +0200

Construction of EasyNVR RTSP to RTMP-HLS Streaming Media Server Front-end: Real-time Dynamic Display of bootstrap-datepicker Calendar Plug-in

EasyNVR has the function of retrieving and playback the video, and first put aside the playback of the video, in order to better user experience, so that users can easily and quickly find the corresponding channel corresponding to the date of the video, is a necessary function. Based on the above requirements, a calendar plug-in is added ...

Posted by briant on Sat, 25 May 2019 01:05:13 +0200

Node.js Template Engine Tutorial-jade Speed Learning and Practical Warfare 1

Environmental preparation: Global installation jade: NPM install jade-g Initialize the project package.json: npm init --yes After the installation is complete, you can use jade --help to view the command line usage of jade 1. Create a new index.jade file under the project directory inde.jade code: 1 doctype html 2 html 3 head 4 met ...

Posted by daucoin on Fri, 24 May 2019 23:15:53 +0200

The three definitions of function in js, function declaration, function homonymy repetition, function deletion,

Full Stack Engineer Development Manual (Author: Luan Peng) js series of tutorials 4-function, function parameters In js, function itself belongs to one kind of object, so it can be defined and assigned as the attribute of object or the parameter of other functions. The function name is only a reference to the object class of the functio ...

Posted by mikelmao on Fri, 24 May 2019 19:35:03 +0200

Simulated electrocardiogram using native js+canvas

From February 2015 to IT industry, it has been nearly two years. From the beginning of java to the front end, we have been groping along the way. All the way to now, the front-end God is absolutely impossible to talk about. At most, it is a beginner. From the beginning of ignorance, to now learning to write github, blog, in fact, there is not m ...

Posted by djalecc on Thu, 23 May 2019 22:57:37 +0200

JS namespace schema parsing

brief introduction See such a question on the SF: For example, for compelling reasons, several global functions need to be written. But I don't want to do that. window.a = function(){} window.b = function(){} window.c = function(){} What's a good way to write this question? Answer: If you use jQuery, you can write as follows $.ex ...

Posted by nightowl on Thu, 23 May 2019 21:21:21 +0200