solved

solutions.sql

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+create database if not exists blog_db;
+use blog_db;
+
+-- Exercise 1
+
+CREATE TABLE IF NOT EXISTS authors (
+    id INT AUTO_INCREMENT PRIMARY KEY,
+    name VARCHAR(100) UNIQUE NOT NULL
+);
+
+CREATE TABLE IF NOT EXISTS posts (
+    id INT AUTO_INCREMENT PRIMARY KEY,
+    title VARCHAR(200) NOT NULL,
+    word_count INT,
+    views INT,
+    author_id INT,
+    FOREIGN KEY (author_id) REFERENCES authors(id)
+);
+
+INSERT INTO authors (name) VALUES
+('Maria Charlotte'),
+('Juan Perez'),
+('Gemma Alcocer');
+
+INSERT INTO posts (title, word_count, views, author_id) VALUES
+('Best Paint Colors', 814, 14, 1),
+('Small Space Decorating Tips', 1146, 221, 2),
+('Hot Accessories', 986, 105, 1),
+('Mixing Textures', 765, 22, 1),
+('Kitchen Refresh', 1242, 307, 2),
+('Homemade Art Hacks', 1002, 193, 1),
+('Refinishing Wood Floors', 1571, 7542, 3);
+
+-- Exercise 2
+
+CREATE TABLE IF NOT EXISTS customers (
+    id INT AUTO_INCREMENT PRIMARY KEY,
+    name VARCHAR(100) NOT NULL,
+    status VARCHAR(20),
+    total_mileage INT
+);
+
+CREATE TABLE IF NOT EXISTS aircrafts (
+    id INT AUTO_INCREMENT PRIMARY KEY,
+    name VARCHAR(50) NOT NULL,
+    total_seats INT
+);
+
+CREATE TABLE IF NOT EXISTS flights (
+    flight_number VARCHAR(10) PRIMARY KEY,
+    mileage INT,
+    aircraft_id INT,
+    FOREIGN KEY (aircraft_id) REFERENCES aircrafts(id)
+);
+
+CREATE TABLE IF NOT EXISTS bookings (
+    id INT AUTO_INCREMENT PRIMARY KEY,
+    customer_id INT,
+    flight_number VARCHAR(10),
+    FOREIGN KEY (customer_id) REFERENCES customers(id),
+    FOREIGN KEY (flight_number) REFERENCES flights(flight_number)
+);
+
+INSERT INTO customers (name, status, total_mileage) VALUES
+('Agustine Riviera', 'Silver', 115235),
+('Alaina Sepulvida', 'None', 6008),
+('Tom Jones', 'Gold', 205767),
+('Sam Rio', 'None', 2653),
+('Jessica James', 'Silver', 127656),
+('Ana Janco', 'Silver', 136773),
+('Jennifer Cortez', 'Gold', 300582),
+('Christian Janco', 'Silver', 14642);
+
+INSERT INTO aircrafts (name, total_seats) VALUES
+('Boeing 747', 400),
+('Airbus A330', 236),
+('Boeing 777', 264);
+
+INSERT INTO flights (flight_number, mileage, aircraft_id) VALUES
+('DL143', 135, 1),
+('DL122', 4370, 2),
+('DL53', 2078, 3),
+('DL222', 1765, 3),
+('DL37', 531, 1);
+
+INSERT INTO bookings (customer_id, flight_number) VALUES
+(1, 'DL143'),
+(1, 'DL122'),
+(2, 'DL122'),
+(3, 'DL122'),
+(3, 'DL53'),
+(4, 'DL143'),
+(3, 'DL222'),
+(5, 'DL143'),
+(6, 'DL222'),
+(7, 'DL222'),
+(5, 'DL122'),
+(4, 'DL37'),
+(8, 'DL222');
+
+-- Exercise 3
+
+SELECT COUNT(DISTINCT flight_number) FROM flights;
+SELECT AVG(mileage) FROM flights;
+SELECT AVG(total_seats) FROM aircrafts;
+SELECT status, AVG(total_mileage) FROM customers GROUP BY status;
+SELECT status, MAX(total_mileage) FROM customers GROUP BY status;
+SELECT COUNT(*) FROM aircrafts WHERE name LIKE '%Boeing%';
+SELECT * FROM flights WHERE mileage BETWEEN 300 AND 2000;
+
+SELECT c.status, AVG(f.mileage)
+FROM bookings b
+JOIN customers c ON b.customer_id = c.id
+JOIN flights f ON b.flight_number = f.flight_number
+GROUP BY c.status;
+
+SELECT a.name, COUNT(*) AS total_bookings
+FROM bookings b
+JOIN customers c ON b.customer_id = c.id
+JOIN flights f ON b.flight_number = f.flight_number
+JOIN aircrafts a ON f.aircraft_id = a.id
+WHERE c.status = 'Gold'
+GROUP BY a.name
+ORDER BY total_bookings DESC
+LIMIT 1;