我在MySQL数据库中有两个表:
照片:
PID - PhotoID [PK],
DateOf - DateTime of uploading,
UID -UserID (owner of the photo)
评级:
WhoUID - UserID who rated,
DateOf - DateTime of rate,
RatingValue - +1 or -1 (positive or negative),
RatingStrength - coefficient (different for each user who vote)
PID - PhotoID, [FK]
我正在构建一个用户在一天(或给定的时间范围)具有各种任务的时间表显示
现在,我通过一次选择当天分配的所有用户,循环遍历他们,并在每个循环中选择用户当天可能有的所有任务来实现这一点。
main选择
SELECT u.id, u.name
FROM users u, assignments a, events e
WHERE u.id = a.u_id AND a.e_id = e.id AND e.date = '{DATE}'
GROUP BY u.id
主select的每个循环中的select
SELECT e.title, e.date
FROM assignment
我有一个定期的活动日历,允许人们注册活动。我有两个表dynamic_events和recurring_events,结构如下:
dynamic events
id (int)
date (date)
time (time)
title (varchar[255])
desc (text)
max_attendees (int)
is_overwrite (tinyint[1])
recurring events
id (int)
day_of_week (int)
time (time)
title (varchar[255])
desc (text)
每当更新重复发生的事件时,我都会使其动