SQL Aliases (AS) 🏷️¶

Mentor's Note: Aliases are like "Nicknames". They don't change the actual name in the database, but they make your results and your code much easier to read. 💡

🌟 The Scenario: The Nickname 📛¶

Actual Name: "Christopher Columbus"
Alias: "Chris"
Technical Column: p_id_001_sales_net
Alias: Price ✅

💻 1. Column Aliases 📊¶

Used to make column headers more descriptive or readable.

-- Scenario: Calculating total price with tax
SELECT 
    product_name, 
    price * 1.18 AS "Price_With_Tax" -- 🏷️ Readable Alias
FROM products;

Rules: - The AS keyword is optional but recommended. - Use Double Quotes " " if the alias has spaces.

💻 2. Table Aliases 🏢¶

Used to shorten table names, especially when joining multiple tables together.

-- Scenario: Fetching employee and department names
SELECT E.name, D.dept_name
FROM employees AS E -- 🏷️ E is easier to type than employees
JOIN departments AS D ON E.dept_id = D.id;

🎨 Visual Logic: The Map¶

Technical Database	Query View (The Alias)
`emp_first_name`	`First_Name`
`dept_loc_zip`	`Zip_Code`
`salary + bonus`	`Total_Pay`

💡 Pro Tip¶

"In Joins, always use Table Aliases (like E for Employees). It prevents 'Ambiguous Column' errors if both tables have a column with the same name (like created_at)."