有没有更好的方法来查看客户在SQL中是否有“休息期”？

SELECT 
    customer_id,
    COUNT(*) AS activity_count
FROM 
    customer_activity
WHERE 
    customer_id = '特定客户ID'
    AND activity_date BETWEEN '开始日期' AND '结束日期'
GROUP BY 
    customer_id;

WITH activity_window AS (
    SELECT 
        customer_id,
        activity_date,
        LAG(activity_date) OVER (PARTITION BY customer_id ORDER BY activity_date) AS prev_activity_date
    FROM 
        customer_activity
)
SELECT 
    customer_id,
    MAX(activity_date) AS last_activity_date,
    MIN(activity_date) AS first_activity_date,
    DATEDIFF(MAX(activity_date), MIN(activity_date)) AS inactive_days
FROM 
    activity_window
WHERE 
    activity_date - prev_activity_date > '休息期天数'
GROUP BY 
    customer_id;

DELIMITER //

CREATE PROCEDURE CheckRestPeriod(IN cust_id INT, IN start_date DATE, IN end_date DATE)
BEGIN
    DECLARE rest_period INT DEFAULT 0;
    
    SELECT 
        COUNT(*) INTO rest_period
    FROM 
        customer_activity
    WHERE 
        customer_id = cust_id
        AND activity_date BETWEEN start_date AND end_date;
    
    IF rest_period = 0 THEN
        SELECT '休息期存在';
    ELSE
        SELECT '休息期不存在';
    END IF;
END //

DELIMITER ;