SQL -通过having分组，连接多个表

CREATE TABLE orders (
  order_id INT PRIMARY KEY,
  customer_id INT,
  order_date DATE,
  amount DECIMAL(10, 2)
);

CREATE TABLE customers (
  customer_id INT PRIMARY KEY,
  customer_name VARCHAR(255),
  country VARCHAR(255)
);

SELECT 
  c.country,
  SUM(o.amount) AS total_amount
FROM 
  orders o
JOIN 
  customers c ON o.customer_id = c.customer_id
GROUP BY 
  c.country
HAVING 
  SUM(o.amount) > 1000;