← К оглавлению занятия

✅ Решения

⚡ Кратко: решения

  • Задание 1 — SELECT SUM(quantity) FROM order_details.
  • Задание 2 — SELECT COUNT(DISTINCT order_id) FROM order_details.
  • Задание 3 — SELECT GROUP_CONCAT(first_name) FROM employees.
  • Задание 4 — SELECT AVG(unit_price), MIN(unit_price), MAX(unit_price) FROM order_details.
  • Задание 5 — группировка по city с сортировкой.
  • Задание 6 — группировка по order_id с суммой quantity.
1

Решение задания 1

SELECT SUM(quantity) AS total_quantity
FROM order_details;
2

Решение задания 2

SELECT COUNT(DISTINCT order_id) AS unique_orders
FROM order_details;
3

Решение задания 3

SELECT GROUP_CONCAT(first_name) AS all_names
FROM employees;
4

Решение задания 4

SELECT AVG(unit_price) AS avg_price,
       MIN(unit_price) AS min_price,
       MAX(unit_price) AS max_price
FROM order_details;
5

Решение задания 5

SELECT city, COUNT(id) AS number_employees
FROM employees
GROUP BY city
ORDER BY number_employees DESC;
6

Решение задания 6

SELECT order_id, SUM(quantity) AS total_quantity
FROM order_details
GROUP BY order_id
ORDER BY total_quantity DESC;
7

Решение задания 7

SELECT company, COUNT(id) AS number_managers
FROM customers
WHERE job_title = 'Purchasing Manager'
GROUP BY company;
8

Решение задания 8

SELECT company, job_title, COUNT(id) AS number_employees
FROM employees
GROUP BY company, job_title;