when a user uses Ctrl+F5 to force a page refresh, the css js html file is reloaded. if the css js html file is not modified, it will take a long time to reload. after looking up the data, you can determine whether the file has been updated by adding...
SELECT COUNT (*) AS num FROM test WHERE ( a = 111AND cid = 21432 OR s_status < > yes OR t_status < > yes ) AND test . delete_time IS NULL LIMIT 1 explain the statement type is displayed as ALL. How to optimize it? ...
because of my interest, I am working on a web application in my spare time. At present, I have a big performance problem. I would like to consult you here. I hope you will not hesitate to give me your advice. there are two tables, one is the exchange ...
select * from a where aa=1 and bb=2; select * from a where in (select id from a where aa=1 and bb=2); ...
A crawler was used before hanging up, and an error of 2006-MySQL server has gone away occurred when entering the library. According to Baidu, change the my.conf file max_allowed_packet=500M wait_timeout=288000 After interactive_timeout = 288000 , t...
concurrency problems can be solved with locks, such as optimistic locks and pessimistic locks, but when you see many references to using redis queues, what is the whole process like? whether it is like this: if you receive a request in the API, push th...
1. The official website begins with an example of listening for a native event on the root element of a component using the .native modifier of v-on, for example, < base-input Vmuri onconcentration focus.native = "onFocus " > < base-input > 2. But ...
Review element found that the second td was not rendered ask the bosses to answer ...
list all the javascript ways you know about reading writing local files, traditional, weird or creative. first give an example to show respect: var fs=require( fs ); fs.readFile( readtxt demo.txt , utf-8 ,function(err,data){ if(err){ ...
use the dialog component in vue-element to display a form in the pop-up window , and use a print button to print the form. Printing uses the window.print () method. because only the part of the pop-up window in the page is printed, the div whose ...