mysql 统计连续

SELECT 
    order_date, 
    COUNT(*) AS consecutive_days
FROM (
    SELECT 
        order_date, 
        @prev_date := order_date,
        IF(@prev_date = DATE_SUB(order_date, INTERVAL 1 DAY), @consecutive_count := @consecutive_count + 1, @consecutive_count := 1) AS consecutive_count,
        @start_date := IF(@consecutive_count = 1, order_date, @start_date)
    FROM 
        orders, 
        (SELECT @prev_date := NULL, @consecutive_count := 0, @start_date := NULL) AS vars
    ORDER BY 
        order_date
) AS subquery
GROUP BY 
    consecutive_count, 
    start_date
ORDER BY 
    consecutive_count DESC;