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SQL/MySQL learning series: Day 4️⃣

Sorry guys I was on a trip for previous few days so there was no new courses during previous week but now its time for: 💥 Day 4 of our SQL series 💥 📘 Lesson 4: Setting Up SQL – Install MySQL/PostgreSQL & Set Up Workbench or DBeaver Before writing your first SQL query, you need a database to work with — and a nice interface to explore it. Here’s a simple guide to setting up your environment: ————————————————— 🔹 Step 1: Choose your database system The most popular free options are: • MySQL – Beginner-friendly and widely used in web development. • PostgreSQL – Open-source, powerful, and great for more complex work. > If you're just starting out: go with MySQL. > If you're curious about more advanced features: try PostgreSQL. ————————————————— 🔹 Step 2: Install the database ✅ For MySQL: • Download: [https://dev.mysql.com/downloads/](https://dev.mysql.com/downloads/) • Install using the MySQL Installer. • Set a root password (don’t forget it!). ✅ For PostgreSQL: • Download: [https://www.postgresql.org/download/](https://www.postgresql.org/download/) • Use the installer for your OS. • Set a password for the "postgres" user during install. ————————————————— 🔹 Step 3: Install a database interface (GUI) Instead of using a terminal, you can write queries in a clean, visual tool: • MySQL Workbench (for MySQL only) →https://www.mysql.com/products/workbench/ • DBeaver (works with MySQL, PostgreSQL & many others) → https://dbeaver.io/ Both are 100% free. ————————————————— 🔹 Step 4: Connect the GUI to your database In the app you installed: • Click New Connection • Choose MySQL or PostgreSQL • Host: localhost • Port: 3306 (MySQL) or 5432 (PostgreSQL) • Username: root (MySQL) or postgres (PostgreSQL) • Password: the one you just created Test the connection – if it says "Success", you’re ready! ✅ ————————————————— 💡 No install? Try online playgrounds If you want to play with SQL right now without setting up anything: • db-fiddle • sqlime ————————————————— Once you’re all set up, let’s move on to writing your first queries!

Here are some additional info about previous SQL database types lesson

SQL/MySQL learning series: Day 3️⃣

👋 Welcome to day 3 of our SQL series ————————————————— 📌 Lesson 3: SQL vs MySQL vs PostgreSQL vs Oracle vs MariaDB vs SQLite – Understanding the Differences 🚀 👋 Now that we know what SQL is, let’s explore the different database systems that use SQL. You know that SQL is a language for talking to databases, right? But SQL itself is NOT a database. It’s just the way we send commands. The actual databases—like MySQL, PostgreSQL, SQLite, and Oracle—are the systems that store and manage data. They all understand SQL, but each has its own special features. So, let’s break them down! 🧐 🟢 What They Have in Common No matter which database you use, SQL lets you: ✅ Store data in tables 📂 ✅ Retrieve data with SELECT 🔍 ✅ Insert new data with INSERT ✏️ ✅ Update existing data with UPDATE 🔄 ✅ Delete data with DELETE ❌ That means if you learn SQL once, you can use it in ANY of these databases! 🙌 But… there are some differences. Let’s compare them! 🟢 Breaking it Down: When to Use Each Database? 🔹 MySQL – Best for web applications (e.g., WordPress, Facebook). 🔹 PostgreSQL – Great for complex queries, data analytics, and apps needing JSON support. 🔹 Oracle DB – Used in banks, large enterprises, and high-security systems. 🔹 SQLite – Ideal for mobile apps and small projects (e.g., Android, iOS apps). 🔹 MariaDB – A faster, open-source alternative to MySQL, often used in place of MySQL. ————————————————— 🟢 SQL vs Database Management Systems (DBMS) Let's clear this confusion as well. SQL is just a language, but to store and manage data, we need a database system. Think of it like this: 💬 SQL = Language 🗣 💾 Database = Storage System 🏛 Different databases use SQL, but they have unique features. Let’s compare the most popular ones. ————————————————— 🟢 Example Queries – Do They Work Everywhere? Most of the syntax is the same across these databases since they all use SQL as the base language. However, there are some small differences in advanced features, functions, or performance optimizations specific to each database. Let’s look at some example queries to see how they might differ. 🔹 Basic Query (Works Everywhere)

    
        SELECT * FROM customers WHERE city = 'London';{}
    

🔹 JSON Query (PostgreSQL Only)

    
        SELECT data->>'name' AS name FROM customers;{}
    

🔹 Limiting Results (Different Syntax) ✅ MySQL, PostgreSQL, SQLite, MariaDB:

    
        SELECT * FROM customers LIMIT 5;{}
    

✅ Oracle:

    
        SELECT * FROM customers FETCH FIRST 5 ROWS ONLY;{}
    

As you can see there are not many differences between those when it comes to syntax 😊 ————————————————— 🟢 So, Which One Should You Learn? 👨‍💻 Just starting out? → MySQL or PostgreSQL are great choices. 📊 Working with analytics? → PostgreSQL is your friend. 🏦 Enterprise work (banks, big companies)? → Oracle DB is common. 📱 Mobile apps or small projects? → SQLite is perfect. 🚀 Looking for a MySQL alternative? → MariaDB is worth checking out. No matter which one you pick, the SQL basics are the same. ————————————————— 🟢 Key Takeaways ✅ SQL is universal, but different databases have different features. ✅ MySQL is great for web apps, PostgreSQL is powerful for large applications. ✅ SQLite is lightweight, Oracle DB is enterprise-level, and MariaDB improves on MySQL. ✅ Most basic SQL commands work across all databases. 📌 Next Lesson: Setting Up Your First Database – Installing MySQL & PostgreSQL. Stay tuned! 🚀

If you like this way of learning show some love ❤️

I just shared this in our @web_dev_bds channel. If your project are using next.js make sure to upgrade to newest version to avoid security risk More info: https://thehackernews.com/2025/03/critical-nextjs-vulnerability-allows.html

🚨 Attention: A Critical Next.js vulnerability What Happened? A massive vulnerability (CVE-2025-29927) was just found in Next.js, a popular framework for building web apps with React. This flaw, rated 9.1/10 for severity, lets attackers slip past security checks using a simple trick—a special header. It affects self-hosted Next.js apps (versions 11.1.4 to 15.2.2) that use middleware to protect pages, like admin dashboards. If unpatched, hackers could access restricted areas—yikes! How Big Is It? Pretty darn big! Millions of developers use Next.js, and this bug leaves tons of apps exposed. The good news? It’s fixed in version 15.2.3 and up. Please update to newest version to stay safe!

SQL/MySQL learning series: Day 2️⃣

👋 Welcome to day 2 of our SQL series ————————————————— 📌 Lesson 1: What is SQL? 🚀 👋 Welcome! Today, we’re starting from the very basics: 🟢 What is SQL? SQL (Structured Query Language) is a language designed to manage and manipulate databases. It's used to: ✅ Store data 📂 ✅ Retrieve data 🔍 ✅ Update data ✏️ ✅ Delete data ❌ 💡 Think of SQL as a way to talk to databases! ————————————————— 🟢 Why is SQL important? SQL is everywhere! It's used in: ✅ Websites & apps (Facebook, Instagram, YouTube) 🌍 ✅ Business intelligence & analytics 📊 ✅ Financial systems 💰 ✅ Data engineering & big data 📡 🚀 If you want to work with data, you need SQL! ————————————————— 🟢 How does SQL work? Databases store data in tables, similar to spreadsheets. Here’s an example table named customers:

    
        +----+---------+----------+
| id | name    | city     |
+----+---------+----------+
|  1 | Alice   | New York |
|  2 | Bob     | London   |
|  3 | Charlie | Berlin   |
+----+---------+----------+{}
    

🔹 Selecting All Data If we want to get everything from this table, we use:

    
        SELECT * FROM customers;{}
    

This means: 💬 “Give me all columns from the customers table.”

————————————————— 🟢 Selecting Specific Columns Sometimes, we don’t need all the data, just specific columns. 🔹 Example: If we only need the names of customers:

    
        SELECT name FROM customers;{}
    

📝 Result:

    
        +---------+
| name    |
+---------+
| Alice   |
| Bob     |
| Charlie |
+---------+{}
    

🔹 Example: If we want names of customers from London:

    
        SELECT name FROM customers WHERE city = 'London';{}
    

📝 Result:

    
        +------+
| name |
+------+
| Bob  |
+------+{}
    

💡 Tip: SQL is case-insensitive, so select, SELECT, and SeLeCt all work the same! ————————————————— 🟢 Key Points to Remember ✅ SQL is a language for managing databases. ✅ It allows you to store, retrieve, update, and delete data. ✅ SQL is used in almost every industry that works with data. ✅ It follows a simple, structured format that makes querying easy. 📌 Next Lesson: SQL vs MySQL vs PostgreSQL vs Oracle vs SQLite – What's the difference? Stay tuned! 🚀

Java 24 Launch (Live from JavaOne 2025) Today is Java 24 release. Stream has just started, but I feel like quality can be a little bit better honestly. You can watch it live here: https://www.youtube.com/watch?v=mk_2MIWxLI0 ~~~ TODAY'S PROGRAM SCHEDULE ~~~ 15:00 UTC: Java 24 Overview with Mikael Vidstedt 15:30 UTC: JavaOne Opening Keynote "Our World, Moved by Java" -- Cutting Edge Demos -- Garbage Collection Performance Insights -- News About Java in Education -- ...and more 17:15 UTC: Java 24 Deep Dive -- AOT Caching with Dan Heidinga -- Stream Gatherers with Viktor Klang

SQL/MySQL learning series: Day 1️⃣

📌 SQL Roadmap: From Zero to Hero 🚀 👋 Welcome! This roadmap will guide you step by step through SQL, from basics to expert level. --- 🟢 Stage 1: Introduction to SQL 🔹 What is SQL? – Structured Query Language for databases. 🔹 SQL vs MySQL vs PostgreSQL vs Oracle vs SQLite – Understanding the differences. 🔹 Setting Up SQL – Install MySQL/PostgreSQL & set up Workbench/DBeaver. --- 🟢 Stage 2: Basic SQL Queries (CRUD Operations) 🔹 Database & Table Basics – Rows, columns, primary keys. 🔹 CREATE TABLE – Defining structure. 🔹 INSERT INTO – Adding data. 🔹 SELECT – Retrieving data. 🔹 UPDATE / DELETE – Modifying & removing data. 🔹 Filtering with `WHERE` – BETWEEN, LIKE, IS NULL. 🔹 Sorting & Limiting – ORDER BY, LIMIT, OFFSET. --- 🟢 Stage 3: Intermediate SQL (Joins, Aggregation, Subqueries) 🔹 Joins (Combining Tables) ✅ INNER JOIN – Matching rows in both tables. ✅ LEFT JOIN / RIGHT JOIN – Keeping all from one table. ✅ FULL OUTER JOIN – All records from both. ✅ CROSS JOIN – Cartesian product. ✅ SELF JOIN – Joining a table to itself. 🔹 Aggregations & Grouping ✅ COUNT(), SUM(), AVG(), MIN(), MAX(). ✅ GROUP BY – Grouping results. ✅ HAVING – Filtering grouped data. 🔹 Subqueries (Nesting Queries) ✅ IN, ANY, ALL, correlated subqueries. 🔹 Common Table Expressions (CTEs) & Views ✅ WITH – Writing reusable queries. ✅ Views – Saving complex queries as virtual tables. --- 🟢 Stage 4: Advanced SQL (Optimization, Transactions, Indexing) 🔹 Performance Optimization ✅ Indexes (CREATE INDEX) for speed. ✅ Using EXPLAIN to analyze queries. 🔹 Transactions & ACID Properties ✅ BEGIN TRANSACTION, COMMIT, ROLLBACK. 🔹 Window Functions (Advanced Analytics) ✅ ROW_NUMBER(), RANK(), DENSE_RANK(). ✅ LAG(), LEAD() for accessing previous/next row values. 🔹 Recursive Queries (Hierarchical Data) ✅ Recursive WITH queries. ✅ Parent-child relationships. --- 🟢 Stage 5: Database Design & Normalization 🔹 Keys: Primary Key, Foreign Key, Composite Key. 🔹 Normalization: ✅ 1NF – No duplicate rows, atomic columns. ✅ 2NF – No partial dependencies. ✅ 3NF – No transitive dependencies. --- 🟢 Stage 6: Advanced Topics (Big Data, NoSQL, SQL in Practice) 🔹 SQL & JSON – Storing/querying JSON in SQL. 🔹 SQL in Data Engineering – Handling large datasets. 🔹 SQL vs NoSQL – When to use which? 🔹 SQL in Real-world Applications – Web apps, BI, ETL. --- 🟢 Stage 7: Mastery & Certifications 🔹 Real-world SQL Projects ✅ Building a Customer Database System. ✅ Creating a Sales Dashboard with SQL. ✅ Automating Data Processing with SQL. 🔹 SQL Certifications ✅ Microsoft SQL Server. ✅ Oracle SQL. ✅ Google Cloud SQL. --- 💡 How to Learn Effectively? ✅ Follow steps in order – Don’t skip fundamentals! ✅ Practice daily – Use LeetCode, Kaggle, open datasets. ✅ Build real-world mini-projects. ✅ Optimize queries – Focus on performance. 📌 What’s Next? Each Monday there will be another lesson explaining each step of this roadmap 🚀

🚀 Let's Learn SQL Together! Starting tomorrow, we’re kicking off a brand-new SQL/MySQL learning series! 🎉 📅 Every Monday we’ll share a new lesson, guiding you step by step—from the fundamentals to more advanced concepts. But first, tomorrow, we’ll drop a roadmap so you know exactly what to expect! I feel like we’ve all been a bit passive here, and this is our chance to do something proactive—to learn, grow, and build real skills together. Your participation is key! If this goes well, we’ll expand into other topics and keep adding valuable content for you. 🔥 Who's in? Drop a 🔥 if you're excited! 🔥 Much love from @bigdataspecialist #SQL #MySQL #LearnTogether #NewSeries