task done

solutions.sql

@@ -0,0 +1,155 @@
+-- exercise 1
+
+DROP DATABASE IF EXISTS blogdb;
+CREATE DATABASE blogdb;
+USE blogdb;
+
+CREATE TABLE authors (
+    id INT PRIMARY KEY AUTO_INCREMENT,
+    name VARCHAR(150) NOT NULL UNIQUE
+);
+
+CREATE TABLE posts (
+    id INT PRIMARY KEY AUTO_INCREMENT,
+    author_id INT NOT NULL,
+    title VARCHAR(200) NOT NULL,
+    word_count INT NOT NULL,
+    views INT NOT NULL,
+    FOREIGN KEY (author_id) REFERENCES authors(id)
+);
+
+INSERT INTO authors (name) VALUES
+('Maria Charlotte'),
+('Juan Perez'),
+('Gemma Alcocer');
+
+INSERT INTO posts (author_id, title, word_count, views) VALUES
+(1, 'Best Paint Colors', 814, 14),
+(2, 'Small Space Decorating Tips', 1146, 221),
+(1, 'Hot Accessories', 986, 105),
+(1, 'Mixing Textures', 765, 22),
+(2, 'Kitchen Refresh', 1242, 307),
+(1, 'Homemade Art Hacks', 1002, 193),
+(3, 'Refinishing Wood Floors', 1571, 7542);
+
+SELECT * FROM authors;
+SELECT * FROM posts;
+
+
+-- exercise 2
+
+DROP DATABASE IF EXISTS airlinedb;
+CREATE DATABASE airlinedb;
+USE airlinedb;
+
+CREATE TABLE aircrafts (
+    id INT PRIMARY KEY,
+    name VARCHAR(100) NOT NULL UNIQUE,
+    total_seats INT NOT NULL
+);
+
+CREATE TABLE flights (
+    flight_number VARCHAR(10) PRIMARY KEY,
+    aircraft_id INT NOT NULL,
+    mileage INT NOT NULL,
+    FOREIGN KEY (aircraft_id) REFERENCES aircrafts(id)
+);
+
+CREATE TABLE customers (
+    id INT PRIMARY KEY,
+    name VARCHAR(150) NOT NULL UNIQUE,
+    status VARCHAR(20) NOT NULL,
+    total_mileage INT NOT NULL
+);
+
+CREATE TABLE bookings (
+    id INT PRIMARY KEY,
+    customer_id INT NOT NULL,
+    flight_number VARCHAR(10) NOT NULL,
+    FOREIGN KEY (customer_id) REFERENCES customers(id),
+    FOREIGN KEY (flight_number) REFERENCES flights(flight_number),
+    UNIQUE (customer_id, flight_number)
+);
+
+INSERT INTO aircrafts VALUES
+(1, 'Boeing 747', 400),
+(2, 'Airbus A330', 236),
+(3, 'Boeing 777', 264);
+
+INSERT INTO flights VALUES
+('DL143', 1, 135),
+('DL122', 2, 4370),
+('DL53', 3, 2078),
+('DL222', 3, 1765),
+('DL37', 1, 531);
+
+INSERT INTO customers VALUES
+(1, 'Agustine Riviera', 'Silver', 115235),
+(2, 'Alaina Sepulvida', 'None', 6008),
+(3, 'Tom Jones', 'Gold', 205767),
+(4, 'Sam Rio', 'None', 2653),
+(5, 'Jessica James', 'Silver', 127656),
+(6, 'Ana Janco', 'Silver', 136773),
+(7, 'Jennifer Cortez', 'Gold', 300582),
+(8, 'Christian Janco', 'Silver', 14642);
+
+INSERT INTO bookings VALUES
+(1, 1, 'DL143'),
+(2, 1, 'DL122'),
+(3, 2, 'DL122'),
+(4, 3, 'DL122'),
+(5, 3, 'DL53'),
+(6, 3, 'DL222'),
+(7, 4, 'DL143'),
+(8, 4, 'DL37'),
+(9, 5, 'DL143'),
+(10, 5, 'DL122'),
+(11, 6, 'DL222'),
+(12, 7, 'DL222'),
+(13, 8, 'DL222');
+
+SELECT * FROM aircrafts;
+SELECT * FROM flights;
+SELECT * FROM customers;
+SELECT * FROM bookings;
+
+
+-- exercuse 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;