关于使用redis防高并发超中奖品设置过期时间的一个疑问

业务 大转盘抽奖活动 奖品分实物和红包 限制用户只能中一个实物 使用redis防同一用户并发超领实物 即中了多个实物获得奖池 {代码...} 若用户还未抽中实物, 且同一用户并发进入, 存在随机选择的奖品都为实物的可能...

滿天的星座 2017-04-25 09:02:25 0  1  900

Data analysis - java data mining analysis ideas

Let me talk about my idea first: monitor the prices of many items on Taobao at the same time, and then obtain the price trends (I plan to write a crawler to obtain this myself, and then store it in the database), but the question arises: how should I store the data so that I can analyze it? Which it...

过去多啦不再A梦 2017-05-17 10:00:51 0  4  760

I'm curious, and I'd like to ask someone to help me. How should I design the order data table for a large shopping volume website like Taobao?

Sorry, I have never done a large website, and I am still not very proficient in databases. If there are hundreds of billions of data in the shopping table, what should be the appropriate value for the primary key id? But since Taobao has developed so far, how has so much Taobao order data been store...

何惜一博 2019-03-29 17:53:28 0  2  1532

Game Development - How to understand animation (Model) in MVC?

In MVC, the data is stored in the Model, and the View is rendered according to the data of the Model. This is a big idea. But for animation, some states will be generated during the gradient process, and these states do not belong to the Model to some extent. For this How does the MVC model solve th...

巴扎黑 2017-05-16 17:06:27 0  1  455

Count the number of Laravel and Mysql related models through intermediate tables using additional conditions.

I have a MySQL query built using Laravel Eloquent's eager loading and withCount functions, but I have some performance issues when dealing with large datasets, is there any way to improve the query below? I need to get all stores and the product quantities related to the stores (via an intermediate ...

P粉514458863 2023-07-24 15:47:02 0  1  620

Export/download Mapbox maps with overlays and markers from HTML

I want to build an HTML page where customers can build their personalized maps. I used Mapbox to create this. There is an overlay on top of this map, and customers can also place markers on the map. But I'm struggling with two big problems: How to get a high quality map image, including overlays and...

P粉459578805 2024-03-29 11:15:04 0  1  508

Ways to fix issue 2003 (HY000): Unable to connect to MySQL server 'db_mysql:3306' (111)

I recently tried to containerize my FastAPIPython server (also for replication/doubling purposes). Before, I had just a MySQL server in a Docker container and everything was fine, but when I also made my web server a service, it couldn't connect to the MySQL server, so now the application doesn't wo...

P粉178132828 2023-09-05 11:18:47 0  1  839

Experiment with sorting after query limit

So this is my first question here, please forgive me if something is wrong. I'm trying to make a sort query based on constraints. So there is a Customers table with 90 records. I want to first perform a query limited to 3 records, and then sort the results of this query by a column called ContactNam...

P粉237125700 2023-09-05 14:46:42 0  1  732

CSS Grid: Create new row when child content overflows column width

I have a two column layout based on CSS grid. When the content of the second column exceeds 1fr I want to create a new row. As it currently stands, the content simply overflows the column. One requirement of this layout is that the items in the right menu column are in one row. I achieve this with: ...

P粉212114661 2023-09-05 15:18:28 0  1  626

PHP full text search functionality using AND, OR and NOT operators

Newbie question: I'm trying to implement a full text search on a search string using php and eloquent. $searchstring="+(victimsuspect)+crime-covid";$searchresult=RssItem::whereRaw("MATCH(description)AGAINST('$searchstring'INBOOLEANMODE)")->ge

P粉076987386 2023-09-05 15:06:32 0  1  595

Shortest way to convert all PHP types to string

I'm writing a general system that I hope can one day be applied to fields like medicine (i.e. it's "scientific"). I think the best way is to represent all the data in php with strings (true will be "true", false will be "false" and so on). The reason for this is that in...

P粉369196603 2023-09-05 15:34:44 0  1  1012

How to get average of DATETIME column in MySQL while grouping by other columns

I'm creating and populating a MySQL table using the following query: SETtime_zone='+00:00';CREATETABLEtimestamp_n_datetime(idINT,timeDATETIME,avg_timeDATETIME);INSERTINTOtimestamp_n_datetime(id,time,avg_time)VALUES("1","2023-01-0310:

P粉460377540 2023-09-05 11:46:21 0  1  517

Multi-device (mobile phone) synchronization - React Native

I'm trying to create a Lightshow that will launch on all users' mobile devices at the same time (can have up to 2000-3000 users). All users will use the Internet (Wi-Fi or mobile data). In our FE we use Apollo for subscriptions and it works like a charm. But the problem is, user A can get subscribed...

P粉151466081 2023-09-05 11:58:38 0  1  704

Spades, Diamonds, Hearts, Clubs => styles do not change font color in Chrome for Android

In Google Chrome on Windows, the card suit symbols (spades, hearts, diamonds, clubs) are colored correctly using the "style" attribute. Unfortunately, the same page displayed in Google Chrome on Android does not display the colors I defined but uses the default black and red. (See the atta...

P粉896751037 2023-09-05 15:25:13 0  1  766