我有两个mysql表,我想做一个选择查询:我的目标是为某个用户计算他从当前时间开始的最后七天的积分。 第一个表为每个订户呈现他从内容id 1 2或3打到特定内容的时间。 他可能在某一天没有内容点击,所以他今天不会得分。
表格显示在这些图片中。 我的选择查询不完整:
SELECT SUM( points ) AS POINT, DAY FROM
(SELECT content_hits.content_id, COUNT( * ) * points AS points,
DATE_FORMAT( hit_time, "%d-%m-%Y" ) AS DAY
FROM content_hits JOIN content
WHERE content_hits.content_id = content.content_id AND subscriber_id =1
AND DATE_FORMAT( hit_time, "%Y-%m-%d" ) > ( CURDATE( ) - INTERVAL 7 DAY )
GROUP BY content_hits.content_id, DAY) AS tm
GROUP BY DAY
ORDER BY DAY DESC
结果如下图所示:
我预计这几天的结果为零:17-7-2102 16-7-2012 15-7-2012 14-7-2012和12-7-2012。 有什么建议吗?
答案 0 :(得分:1)
需要创建用于左连接的日历表
CREATE TABLE ints (i INTEGER);
INSERT INTO ints VALUES (0), (1), (2), (3), (4), (5), (6), (7), (8), (9);
将日历表连接到您的查询。
SELECT cal.date,COALESCE(a.point,0) as point
FROM (
SELECT DATE_FORMAT(CURDATE() + INTERVAL a.i * 10 - b.i DAY,"%Y-%m-%d") as date
FROM ints a JOIN ints b
ORDER BY a.i * 10 - b.i
) cal LEFT JOIN
(SELECT SUM( points ) AS POINT, DAY FROM
(SELECT content_hits.content_id, COUNT( * ) * points AS points,
DATE_FORMAT( hit_time, "%Y-%m-%d" ) AS DAY
FROM content_hits JOIN content
WHERE content_hits.content_id = content.content_id AND subscriber_id =1
AND DATE_FORMAT( hit_time, "%Y-%m-%d" ) > ( CURDATE( ) - INTERVAL 7 DAY )
GROUP BY content_hits.content_id, DAY) AS tm
GROUP BY DAY
)a
ON cal.date = a.day
WHERE cal.date BETWEEN CURDATE( ) - INTERVAL 7 DAY AND CURDATE()
ORDER BY cal.date desc;
SQL DEMO此处。