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 ...
my statement is select user_vip_card . , flow_of_vipcard . , if ((user_vip_card.max_times IS NULL OR user_vip_card.max_times= 0 OR user_vip_card.max_times=9999),-1, (user_vip_card.max_times-count (flow_of_vipcard.id) AS remain_times ...
after using the echarts4.0 version, the word cloud color will be lost, and echarts-wordcloud supports up to the echats3.6 version. If you use the echats3.6 version of the existing chart will be invalid, there is no solution to greatly help me ...
as mentioned, how does PHP convert time () * 1000 to a string in Y-m-d H:i:s format ...
this and that question is very important how to safely install webpack and uninstall webpack. The main purpose is to prevent webpack from breaking down and come back from the west. Ask the old driver to lead the way. When you go back at night, you may h...
post a piece of code I saw on Zhihu, but I haven t figured it out for a long time. Ask the great god for a popular explanation: <?php namespace App; interface Middleware { public function handle($next); } class Session implements Middleware ...