Data Analyst

Chapter 4 — MySQL: Database Foundations

📚 Chapter Overview

Databases are the engine behind data storage. In this chapter, you will learn the basics of SQL (Structured Query Language), create your first database, and master the art of selecting and filtering data.

Learning Objectives:

4.1 SQL Basics: CRUD Operations

Part 1 — Definition

SQL is the standard language for dealing with Relational Databases. The most common operations are CRUD: Create (INSERT), Read (SELECT), Update (UPDATE), and Delete (DELETE). Data is stored in Tables consisting of rows and columns.

Part 2 — Syntax

CREATE TABLE students (id INT, name VARCHAR(50));
INSERT INTO students VALUES (1, 'Ali');
SELECT * FROM students;

Part 3 — Example

Problem: Select only the students who are older than 20.

SELECT name, age
FROM students
WHERE age > 20;

Observation: The WHERE clause is the most important tool for filtering large datasets down to what you actually need.

Part 4 — Video

Video: Coming Soon

4.2 Sorting and Distinct Values

Part 1 — Definition

Often, you need to see unique values or sort your data. DISTINCT removes duplicates from your results, and ORDER BY sorts the data ascending (ASC) or descending (DESC).

Part 2 — Syntax

SELECT DISTINCT city FROM customers;
SELECT * FROM orders ORDER BY amount DESC;

Part 3 — Example

Problem: Find all unique regions where we have customers, sorted alphabetically.

SELECT DISTINCT region
FROM customers
ORDER BY region ASC;

Part 4 — Video

Video: Coming Soon

🏆 Chapter Challenge

Challenge Objective

Create and Query a "Product Inventory" database.

Requirements

Step-by-Step Process

  1. Run the CREATE TABLE command.
  2. Perform 5 INSERT operations.
  3. Use SELECT * FROM products WHERE ... to get the result.

Expected Deliverables