Why ordering matters in SQL - See It in Action

Why Ordering Matters in SQL Queries

📖 Scenario: You are working with a small bookstore database. You want to see the list of books sorted by their price to decide which books to promote.

🎯 Goal: Build a SQL query that retrieves book titles and prices from the books table and orders the results by price in ascending order.

📋 What You'll Learn

Create a table called books with columns id, title, and price

Insert three books with exact titles and prices

Write a SELECT query to get title and price from books

Order the results by price in ascending order

💡 Why This Matters

🌍 Real World

Ordering data is important in real databases to show results in a meaningful way, like cheapest to most expensive products.

💼 Career

Database developers and analysts often write queries with ORDER BY to prepare reports and dashboards.

1

Create the books table and insert data

Create a table called books with columns id (integer), title (text), and price (decimal). Then insert these three books exactly: (1, 'The Art of SQL', 30.00), (2, 'Learning Databases', 25.50), and (3, 'SQL Basics', 20.00).

SQL

-- Create the books table and insert the three books
-- Your code here

Need a hint?

Use CREATE TABLE to define the table and INSERT INTO to add the rows.

2

Set up the SELECT query

Write a SELECT query that retrieves the title and price columns from the books table.

SQL

CREATE TABLE books (
  id INTEGER,
  title TEXT,
  price DECIMAL
);

INSERT INTO books (id, title, price) VALUES
  (1, 'The Art of SQL', 30.00),
  (2, 'Learning Databases', 25.50),
  (3, 'SQL Basics', 20.00);

-- Write SELECT query to get title and price from books
-- Your code here

Need a hint?

Use SELECT title, price FROM books; to get the columns.

3

Add ordering by price

Modify the SELECT query to order the results by the price column in ascending order using ORDER BY price ASC.

SQL

CREATE TABLE books (
  id INTEGER,
  title TEXT,
  price DECIMAL
);

INSERT INTO books (id, title, price) VALUES
  (1, 'The Art of SQL', 30.00),
  (2, 'Learning Databases', 25.50),
  (3, 'SQL Basics', 20.00);

-- Modify the SELECT query to order by price ascending
-- Your code here

Need a hint?

Add ORDER BY price ASC at the end of the SELECT query.

4

Complete the query with descending order

Change the ORDER BY clause to sort the books by price in descending order using ORDER BY price DESC.

SQL

CREATE TABLE books (
  id INTEGER,
  title TEXT,
  price DECIMAL
);

INSERT INTO books (id, title, price) VALUES
  (1, 'The Art of SQL', 30.00),
  (2, 'Learning Databases', 25.50),
  (3, 'SQL Basics', 20.00);

-- Change ORDER BY to sort by price descending
-- Your code here

Need a hint?

Replace ASC with DESC in the ORDER BY clause.