Little T Introduction: In order to help applications obtain data written to the Time Series Database (Time Series Database) TDengine in real time, or process data in the order of event arrival, TDengine provides a data subscription and consumption interface similar to message queue products. In this way, in many scenarios, the time series data […]
Tag: subscript
React [Context_function, function component subscription Context, Fragments, error boundary_concept, error boundary_application, Refs & DOM] (4)
Table of Contents Context_role Function component subscribes to Context Fragments Error Boundary_Concept Error Boundary_Application Refs & DOM Context_role Data in React components is passed from top to bottom (from parent to child) through the props attribute, but sometimes some components in the middle may not need the value of props. //App.js return ( <div> <ContextTest […]
postgresql data subscription
Previous situation The transaction log is an important part of the database and stores the history of all changes and operations in the database system to ensure that the database does not lose data due to failures (such as power outages or other failures that cause the server to crash). In PostgreSQL (hereinafter referred to […]
SuperSubScriptHelper–Unicode superscript and subscript helper class
During the implementation of the project, superscript and subscript characters need to be processed, such as chemical formulas, squares, cubes, etc. There are roughly two ways to implement superscript and subscript characters. One is that the characters themselves contain superscript and subscript information, and the other is that the superscript and subscript characters are displayed […]
[C++ Operator Overloading] Explore the subscript operator [] overloading in C++
Directory title Exploring subscript operator overloading in C++ Introduction What is the subscript operator []? Why do we need to overload the subscript operator? How to overload the subscript operator? Basic Grammar Code example Notes and best practices Summary Conclusion Exploring subscript operator overloading in C++ Introduction In C++ programming, operator overloading is a very […]
Component Communication in React 02 – Message Subscription and Publishing, Unsubscription and Unsubscription when Uninstalling a Component
Component Communication in React 02 – Message Subscription and Publishing, Unsubscription and Unsubscription when Uninstalling a Component 1 Introduction 1.1 Communication using props 1.2 About useEffect 2. Install pubsub-js 3. Message subscription and publishing 3.1 Simple example-1 3.2 Simple example-2 (improvement, optimization) – subscribe to messages + use messages 4. Unsubscribe 4.1 Cancel a single […]
mqtt message subscription mechanism
Implementing the MQTT protocol requires communication between the client and the server. During the communication process, there are three identities in the MQTT protocol: Publisher (Publish), Broker (server), Subscribe. Among them, the message publisher and subscriber are both clients, the message agent is the server, and the message publisher can be a subscriber at the […]
Use stompjs to implement Websocket instant messaging subscription and publishing
Instant messaging is often used in daily development to achieve real-time updates of messages. 1. Use polling for query (if the status does not change for a long time under a certain situation, the client’s frequent calling of the interface will cause a waste of resources) 2. Use websockets The following examples use stompjs and […]
About the application of Subscription in Angular development
In Angular applications, Subscription is part of the RxJS (Reactive Extensions for JavaScript) library and is used to manage subscriptions to Observables. Subscriptions are a mechanism used in reactive programming that allow us to perform actions when an observed object emits a new value. In Angular, the Subscription class is often used to handle the […]
Product of two numbers: Output the product of two numbers in a scrambled list of integers from 1 to 100 that is the smallest subscript pair of the target integer.
Given a scrambled list of integers from 1 to 100, find and output two integer subscript pairs whose product is the user-specified integer. (This note is suitable for coders who are proficient in Python lists) [The details of learning are a joyful process] Python official website: python cutting edge. Unfortunately it’s the original English version. […]