SQL (Structured Query Language) is a powerful tool for managing and manipulating relational databases. Whether you're a beginner or looking to refine your skills, this guide will walk you through the essentials.

🧩 1. SQL Basics

  • What is SQL?
    SQL is a standard programming language used to interact with databases. It allows you to perform tasks like creating tables, inserting data, and querying information.

    SQL Basics

  • Key Concepts

    • Databases
    • Tables
    • Queries
    • Constraints

📊 2. Writing Your First Query

  • SELECT Statement 

    SELECT * FROM employees;

    This retrieves all records from the employees table.

    SELECT Statement

  • Filtering Data
    Use WHERE to narrow results: 

    SELECT name FROM employees WHERE department = 'Sales';

🛠️ 3. Data Manipulation

  • INSERT, UPDATE, DELETE

    • Insert new records: INSERT INTO table (columns) VALUES (data);
    • Update existing records: UPDATE table SET column = value WHERE condition;
    • Delete records: DELETE FROM table WHERE condition;
    Data Manipulation

📁 4. Advanced Topics

  • Joins
    Combine data from multiple tables using JOIN clauses.

  • Aggregation
    Use GROUP BY and ORDER BY for summarizing data.

  • Subqueries
    Nest queries within others to retrieve dynamic data.

    SQL Advanced

🌐 Expand Your Knowledge

Ready to dive deeper? Explore our SQL Queries Guide for practical examples or check out Database Design Fundamentals to build your skills further.

Database Design

Let me know if you'd like to practice with exercises or need help with specific SQL challenges! 😊