SQL/MySQL learning series: Day 2️⃣

👋 Welcome to day 2 of our SQL series

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📌 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!

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🟢 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!

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🟢 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.”

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🟢 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!

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🟢 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! 🚀