创建自定义事件时间表。我应该使用 "LIKE" 吗？

Question

我正在创建一个活动事件调度程序，它允许 "Every Monday"、"May 6th through 10th"、"Every day except Sunday" 等频率

我想出了一个解决方案，我相信它会很好地工作（尚未实施），但是，它在查询中使用了 "LIKE"，我一直不太喜欢。如果有人有建议可以用更清洁的方法达到相同的结果，请提出来！

+----------------------+
| Campaign Table       |
+----------------------+
| id:int               |
| event_id:foreign_key |
| start_at:datetime    |
| end_at:datetime      |
+----------------------+

+-----------------------------+
| Event Table                 |
+-----------------------------+
| id:int                      |
| valid_days_of_week:string   |  < * = ALL. 345 = Tue, Wed, Thur. etc.
| valid_weeks_of_month:string |  < * = ALL. 25 = 2nd and 5th weeks of a month.
| valid_day_numbers:string    |  < * = ALL. L = last. 2,7,17,29 = 2nd day, 7th, 17th, 29th,. etc.
+-----------------------------+

活动日程示例如下所示：

valid_days_of_week = '1357' (Sun, Tue, Thu, Sat)
valid_weeks_of_month = '*' (All weeks)
valid_day_numbers = ',1,2,5,6,8,9,25,30,'

以今天（6/25/15）为例，我们有以下信息可以查询：

Day of week: 5 (Thursday)
Week of month: 4 (4th week in June)
Day number: 25

因此，要获取今天的所有事件，查询将如下所示：

SELECT c.*
  FROM campaigns AS c,
  LEFT JOIN events AS e
    ON c.event_id = e.id
WHERE
  ( e.valid_days_of_week = '*' OR e.valid_days_of_week LIKE '%5%' )
    AND ( e.valid_weeks_of_month = '*' OR e.valid_weeks_of_month LIKE '%4%' )
    AND ( e.valid_day_numbers = '*' OR e.valid_day_numbers LIKE '%,25,%' )

那个（未经测试的）查询理想情况下 return 上面的示例事件。 "LIKE" 查询让我担心。我希望这些查询更快。

顺便说一下，我正在使用 PostgreSQL

期待优秀的回复！

Answer 1

使用数组：

CREATE TABLE events (id INT NOT NULL, dow INT[], wom INT[], dn INT[]);

CREATE INDEX ix_events_dow ON events USING GIST(dow);
CREATE INDEX ix_events_wom ON events USING GIST(wom);
CREATE INDEX ix_events_dn ON events USING GIST(dn);

INSERT
INTO    events
VALUES  (1, '{1,3,5,7}', '{0}', '{1,2,5,6,8,9,25,30}'); -- 0 means any

，则查询：

SELECT  *
FROM    events
WHERE   dow && '{0, 5}'::INT[]
        AND wom && '{0, 4}'::INT[]
        AND dn && '{0, 26}'::INT[]

这将允许使用索引来过滤数据。

创建自定义事件时间表。我应该使用 "LIKE" 吗？

Creating custom event schedules. Should I use "LIKE"?

sql

database

postgresql

database-design