我在计算本周夏天和上周夏天的差值。这些值都存储在一个表中。
我已经有了当前和上周的单个值，但是如何在select中得到它们，这些值可以相互抵消，差异可以用百分比显示。
例如，输出必须显示：+10%或-10%，这取决于当前值是高于还是低于最后一个值。
我试过了，但总是出现错误：

SELECT views_current_week / views_last_week * 100 AS difference 
FROM (
    SELECT SUM(website_stats_homepage) as views_last_week  
    FROM website_stats 
    WHERE website_stats_date >= curdate() - INTERVAL dayofweek(curdate())+6 day 
        AND website_stats_date < curdate() - INTERVAL dayofweek(curdate())-1 day, 
    SELECT SUM(website_stats_homepage) as views_current_week 
    FROM website_stats 
    WHERE yearweek(DATE(website_stats_date), 1) = yearweek(curdate(), 1)) 
website_stats