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Showing posts from April, 2025

What Is SQLite?

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  What Is SQLite? SQLite is a C-language library designed to implement a compact, high-speed, self-contained, and robust SQL database engine . It stands as the most widely employed database engine globally, integral to the operating systems of virtually all mobile phones and the majority of computers. Additionally, it is packaged within numerous everyday applications. The SQLite file format boasts stability, cross-platform compatibility, and backward compatibility. Developers commit to maintaining this stability until the year 2050. SQLite database files serve as prevalent containers for the exchange of rich content across systems and as a long-term archival format for data . The active usage of SQLite databases exceeds a staggering 1 trillion (1e12) instances [5]. It is noteworthy that the SQLite source code is in the public domain, making it freely accessible for use by anyone, without restrictions on purpose. Learn SQLite with us at PCWorkshops.     ...

What is Relationship Cardinality?

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  What is Relationship Cardinality ? Relationship cardinality refers to the number of instances of one entity that can be associated with instances of another entity in a database. It defines the type of relationship between two entities and plays a crucial role in database design. The most common types of relationship cardinality are: One-to-One (1:1) : Each record in one table is linked to exactly one record in another table. For example, one person may have one passport. One-to-Many (1:N) : One record in a table can be associated with multiple records in another table, but each record in the second table is linked to only one record in the first table. For instance, one department can have many employees. Many-to-One (N:1) : The inverse of o ne-to-many , where multiple records in a table can be associated with a single record in another table, such as many orders linked to one customer. Many-to-Many (N:M) : Multiple...

What is an ERD Diagram?

  What is an ERD Diagram? In the realm of database design, an Entity- Relationship Diagram (ERD) serves as a powerful visual tool for illustrating the relationships between entities. This modeling technique provides a clear and concise representation of the database structure, aiding communication during the design phase. ERDs play a pivotal role in conveying the logical framework of a database to key stakeholders, encompassing developers, business analysts, and database administrators. Learn more on our course. Notable components integral to an ERD encompass: 1. Entities : These signify objects or concepts that store data within the database. E.g., customers, products, employees, and more. 2.      Attributes: Attributes encapsulate the properties or characteristics of entities. For instance, a "Customer" entity might possess attributes such as "CustomerID," "Name," "Email," and "Phone." 3.      Relationships: ...

SQL: What is and Active vs. Inactive Relationships

  SQL: What is and Active vs. Inactive Relationships   In database design, Active  relationships  are those that are currently being used in queries, meaning they are directly involved in filtering, joining, or processing data. These relationships are essential for the functioning of the system.   Inactive  relationships  , on the other hand, are relationships that exist in the schema but are not currently active in the data processing. They may be used for specific purposes or are available for potential future use but are not directly involved in query operations unless explicitly activated.   Do the full course:  SQl Course

Can You Name 20 Databases That Use SQL?

 Can You Name 20 Databases That Use SQL ? Here are 20 popular databases that use SQL: MySQL – Open-source, widely used for web applications. PostgreSQL – Advanced, open-source, with extensive features. Microsoft SQL Server – Microsoft's enterprise-level database. Oracle Database – Powerful, widely used for enterprise applications. SQLite – Lightweight, embedded database often used in mobile applications. MariaDB – Fork of MySQL, commonly used in web applications. IBM Db2 – IBM’s database system, used in enterprise applications. Amazon RDS – Managed SQL database service by AWS. Google Cloud SQL – Fully-managed database service by Google Cloud. Amazon Aurora – High-performance, cloud-native relational database. SAP HANA – High-performance, in-memory database. Sybase ASE (Adaptive Server Enterprise) – Used in financial and enterprise environments. Microsoft Access – Lightwe...

What is the difference between a Crypto Currency Coin and a Crypto Token

What is the difference between a Crypto Currency Coin and a Crypto Token The main difference between a cryptocurrency coin and a token is how they are built and used: 1. Cryptocurrency Coin Has its own blockchain: Coins operate on their own independent blockchain (e.g., Bitcoin runs on the Bitcoin blockchain, and Ethereum runs on the Ethereum blockchain). Used for transactions: Coins are primarily used as a form of digital currency (e.g., Bitcoin (BTC) is used for payments and as a store of value). Examples: Bitcoin (BTC), Ethereum (ETH), Binance Coin (BNB - now on BNB Chain), Solana (SOL). 2. Cryptocurrency Token Built on an existing blockchain : Tokens are created on top of an existing blockchain, like Ethereum, Solana, or Binance Smart Chain, using smart contracts. Used for various purposes : tokens can represent assets (like stablecoins or NFTs), be used in DeFi applications, or grant governance rights in DAOs. 3. Examples: Utility Tokens : Chainlink (LINK), Uniswap (UNI) Stableco...

20 Java Web Scraping Tips

20 Java Web Scraping Tips  1/20: 🚀 Want to learn Web Scraping with Java ? Let's break it down step by step! In this thread, we'll cover: ✔️ Setting up ✔️ Fetching web pages ✔️ Parsing HTML ✔️ Handling dynamic content Let's go! 🧵👇  Java 2/20: 🔧 Step 1: Set Up Your Project You'll need: ✅  Java  (JDK 8+) ✅ Maven or Gradle ✅  Java  JSoup (for parsing HTML) Add this dependency in pom.xml: <dependency>     <groupId>org.jsoup</groupId>     <artifactId>jsoup</artifactId>     <version>1.16.1</version> </dependency>  Java 3/20: 📡 Step 2: Fetch a Web Page Use JSoup to download a webpage in  Java : Document doc = Jsoup.connect("https://example.com").get(); System.out.println(doc.title()); This prints the page title! 🎯 4/20: 📌 Step 3: Extract Data from HTML Find elements using CSS selectors: Elements links = doc.select("a"); for (Element link : links) {     System.ou...