mysql 时间范围分组

SELECT 
    DATE(order_time) AS order_date, 
    SUM(amount) AS total_amount
FROM 
    orders
GROUP BY 
    order_date
ORDER BY 
    order_date;

SELECT 
    dates.date AS order_date, 
    COALESCE(SUM(o.amount), 0) AS total_amount
FROM 
    (SELECT DATE_SUB(CURDATE(), INTERVAL n DAY) AS date FROM numbers WHERE n >= 0 LIMIT 30) AS dates
LEFT JOIN 
    orders o ON DATE(o.order_time) = dates.date
GROUP BY 
    dates.date
ORDER BY 
    dates.date;

SELECT 
    CONVERT_TZ(order_time, 'UTC', 'Asia/Shanghai') AS local_order_time, 
    SUM(amount) AS total_amount
FROM 
    orders
GROUP BY 
    local_order_time
ORDER BY 
    local_order_time;