Tag：Matters needing attention
-
Time：2021-2-21
Compared with Java keyboard input, C language scanf has some details that need to be paid attention to. In order to avoid stepping on the pit when using, let’s take a look at scanf. Scanf() is a format input function of C language, which is declared in stdio. H header file just like printf function […]
-
Time：2021-2-12
When a query is a condition of another query, it is called a subquery. Subquery can use several simple commands to construct powerful compound commands. Subqueries are most commonly used in the where clause of the select-sql command. A subquery is a select statement, nested in a select, select… Into, insert… Into, delete, or update […]
-
Time：2021-2-9
Read this article tips: This article is suitable for chewing slowly, do not read at a glance, or you will miss a lot of valuable details. The article begins with the official account.Learn big data in five minutes preface SQL is the most commonly used in data warehouse construction and data analysis. Its syntax is […]
-
Time：2021-1-31
2D transform Transform is a new attribute in CSS3, which can realize the effect of rotation, displacement, scaling and so on Two dimensional coordinate system 2D conversion is a technique to change the shape and position of elements in two-dimensional plane Translate (displacement) matters needing attention The so-called displacement is moving along the X and […]
-
Time：2021-1-6
preface Practice is often more important than seeing Construction of stand alone docker version: ‘2’ services: zookeeper: image: wurstmeister/zookeeper ports: – “2181:2181” kafka: image: wurstmeister/kafka depends_on: [ zookeeper ] ports: – “9092:9092” environment: KAFKA_ADVERTISED_HOST_NAME: kafka KAFKA_ADVERTISED_PORT: 9092 KAFKA_CREATE_TOPICS: “test:1:1” KAFKA_ZOOKEEPER_CONNECT: “zookeeper:2181” matters needing attention: If you want the Java client to connect to Kafka normally, […]
-
Time：2020-12-12
1. The concept of OO CSS OSS CSS abstracts the reusable elements of a page into a class, which is described by class, and the corresponding HTML can be regarded as an instance of this class 2. The function and notice of OO CSS effect (1) Strengthen code reuse for easy maintenance(2) Reduce CSS volume(3) […]
-
Time：2020-12-11
Recently, I have nothing to do. I found the API about the recent epidemic on the Internet. I intend to make it easy for my family to check the new pneumonia. (the emphasis is casual. The total time for doing this is less than an hour.) Tianxing data API: https://www.tianapi.com/ Demo：https://demo.0vov.com/xfy.html github：https://github.com/DuJiu02/XinFeiYan I have […]
-
Time：2020-12-5
gollumIt is a wiki that can be written with markdown. During the installation process, record it. Introduction to Gollum characteristicThere are the following aspects: * lightweight * use Markdown * web-based * Can be easily stored in GitGitHub address isGollum,It’s a Sinatra based application. It supports, amongst others, Markdown. Evertime you make a change, it […]
-
Time：2020-12-3
Elasticsearch is a distributed and restful search and data analysis engine. ——Elastic stack official website Building elasticsearch’s “things”“ One day, on the deck of the golden Melly, Weibo told Saab that it was necessary to use elasticsearch database in the following project development process, which was mainly used for real-time query of data collected by […]
-
Time：2020-12-2
Elasticsearch is a distributed and restful search and data analysis engine. ——Elastic stack official website Building elasticsearch’s “things”“ One day, on the deck of the golden Melly, Weibo told Saab that it was necessary to use elasticsearch database in the following project development process, which was mainly used for real-time query of data collected by […]
-
Time：2020-11-11
1. What is annotation In the daily development of new Java classes, we use class and interface more often. Like them, annotations are a kind of type. The modifier [email protected], as shown in the figure below Simple use of annotations 2. Notes provided by JDK The following are the built-in annotations provided by Java that […]
-
Time：2020-10-30
PHP regular matching Chinese @author: CooperZhang Regular matching character set [\ x {4e00} – \ x {9fa5}] matters needing attention: At the end of the regular expression, u should be added/^…$/u 1、 All matches are in Chinese /^[\x{4e00}-\x{9fa5}]+$/u 2、 Match contains Chinese /[\x{4e00}-\x{9fa5}]+/u 3、 Match Chinese and English (including symbols)_) /[\w\x{4e00}-\x{9fa5}]+/u Regular matching Match Chinese […]
