have a question about SQL: about the left join implementation of PostgreSQL or MySQL suppose: table structure table_name :user uid name 1 2 3 table_name : age uid age 1 10 2 20 3 30 4 40 SQL: 1: SELECT ...
var canvas = document.getElementById( poster ); var windowWidth = $(window).width(); var windowHeight = $(window).height(); console.log(windowWidth, windowHeight) canvas.width = windowWidth * 0.76; canvas.height = canvas.width *...
there is a column of numbers in my file, which looks like: 1 2 7 8 9 12 17 21 22 23 I want to get three consecutive numbers and output them. For example, in the above file, the result I want to get is . 7 8 9 I would like to ask you, how should it b...
use the cordova serve command to debug on the browser. When you find that you have entered the page, there is no response. Modify the index file in the www directory and find that it is caused by the cordova.js file. Have you ever encountered this proble...
js calls Android for voice recording Android returns the absolute path and duration of the audio file but how does js get the audio file through the absolute path and transfer the file to the background through file ...
can you think of a page of Mini Program as a single-page application of vue? So multiple pages are multiple single-page applications, or is it that a Mini Program is just a single-page application, and multiple pages in it are routing pages? ...