如何使用SQL语句在MySQL中进行复杂的数据计算和处理？

SELECT SUM(total_price) AS total_sum FROM orders;

SELECT AVG(total_price) AS avg_price FROM orders;

SELECT MAX(total_price) AS max_price, customer_id FROM orders GROUP BY customer_id ORDER BY max_price DESC LIMIT 1;

SELECT customer_id, total_price 
FROM orders 
WHERE (customer_id, created_at) IN (SELECT customer_id, MAX(created_at) FROM orders GROUP BY customer_id);

DELETE FROM customers WHERE id IN (SELECT DISTINCT customer_id FROM orders GROUP BY customer_id HAVING SUM(total_price) < 100);

SELECT customers.id, customers.name, SUM(orders.total_price) AS total_order_sum, SUM(payments.amount) AS total_payment_sum 
FROM customers 
LEFT JOIN orders ON customers.id = orders.customer_id 
LEFT JOIN payments ON customers.id = payments.customer_id 
GROUP BY customers.id;

SELECT customer_id FROM orders GROUP BY customer_id HAVING COUNT(*) >= 2;