SELECT within SELECT

1. List the name s of each country, in which population is higher than that of Russia. SELECT name FROM world WHERE population > (SELECT population FROM world WHERE name='Russia'); 2. List the per capita GDP of each country in Europe, of which the per capita GDP is higher than that ...

Posted on Mon, 05 Aug 2019 00:16:56 -0400 by Hiro

CSS Writes a Store Card Ticket

Still worrying about the various formats of store card tickets above? CSS is not familiar, canvas is too difficult, what to do? Let's prepare the basics. radial-gradient background: radial-gradient(shape size at position, start-color, ..., last-color); value describe shape Determine the type of circle: Ellipse (default): Specifies th ...

Posted on Sun, 04 Aug 2019 22:55:21 -0400 by iloveny

[JDK] JDK Source Analysis - AbstractQueued Synchronizer

Summary   Previous article JDK Source Analysis - AbstractQueued Synchronizer (1) "Preliminary analysis of AQS, which refers to Node node's"exclusive mode"and"sharing mode", in fact, AQS is mainly around the operation of these two modes.   Node node is the encapsulation of thread Thread class, so the two modes can be ...

Posted on Sun, 04 Aug 2019 10:46:50 -0400 by sgoldenb

Beauty of Programming Quickly Finds Faulty Machines

Let's take a look at the title of "The Beauty of Programming". The title is as follows:Assuming that only one machine stores a record labeled ID (ID is less than 1 billion integers), and that each data holds two backups, two machines store the same data.1. At a certain time, if you get a list of data file IDs, can you quickly find out ...

Posted on Sun, 04 Aug 2019 10:15:46 -0400 by unknown1

Conceptual Understanding of NMS (Non-Maximum Suppression) in Target Detection

Links to the original text: https://blog.csdn.net/sinat_34474705/article/details/80045294 Reference Blog Transfer Learning, IOU and NMS Understanding of Some Common Concepts in Object Detection Target Location and Detection Series (3): ...

Posted on Sun, 04 Aug 2019 06:53:09 -0400 by ieda

Mobile Common Troubleshooting

In the normal development process, often encounter some difficulties and complications, here record the commonly used solutions. 0.5px line requested by Miss UI Reason: Compatibility is different for different mobile phones, especially Android The Safari performance of IOS is good, and safari can support floating-point attributes.Therefore, 0 ...

Posted on Sat, 03 Aug 2019 01:08:44 -0400 by mshen

Actual Vue 7th Day: Implementing Drag Sorting Function

Actual Vue 7th Day: Implementing Drag Sorting Function Preface I. Functional Description 2. Code Implementation Summary of using draggable components Complete Code Preface In the previous section Actual Vue Day 6: Implementing Adding and Deleting Common Application Functions Speaking of deleting ...

Posted on Fri, 02 Aug 2019 07:02:08 -0400 by The Silent

java High Concurrency Series - Day 20: Executor Framework in JUC 2

This is the 20th article in the java high concurrency series. Content of this article Background of Executor Completion Service Introduce Completion Service Interface and Common Methods Introduce ExecutorCompletionService class and its principle Example: Execute a batch of tasks, then consume the execution results Example [2 ways]: Asynchronou ...

Posted on Fri, 02 Aug 2019 06:26:15 -0400 by bedrosamo

Is there any relationship between distance and delay?

The question I want to discuss with you today is: Does the flight distance have anything to do with the delay time? Our data is the flight data of the nycflights 13 package in R. Okay, move the bench, we need to start the analysis. Let's take a brief look at our data first. > install.packages("dply ...

Posted on Fri, 02 Aug 2019 05:18:12 -0400 by kardiostep

Responding and Posting Functions of Small Program Comments

This time share "post function", this function is actually very risky, especially for some sensitive speech control, if not done well, it may lead to the closure of small programs, so in addition to the necessary manual audit and inspection, we need some help from Wechat security monitoring API, under the auspices of AI, now many big ...

Posted on Fri, 02 Aug 2019 04:05:31 -0400 by MarCn