存储工作时间并有效查询的最佳方式

Question

我打算为商店存储工作时间.我想知道什么是工作时间字段的最佳建模,以便我能够以非常有效的方式获得当前时刻的开放/封闭商店列表.

Answer 1

要存储正常的操作时间,您需要存储包含以下内容的许多记录:

• 商店 - INTEGER
• DayOfWeek - INTEGER(0-6)
• OpenTime - TIME
• 关闭时间 - 时间

例如,我假设每家商店在国定假日期间减少了工作时间,或者工厂停工,因此您还需要存储一些覆盖记录:

• 商店 - INTEGER
• OverrideStartDate - DATE
• OverrideEndDate - DATE
• DayOfWeek - INTEGER(0-6)
• AltOpenTime - TIME
• AltCloseTime - TIME
• 已关闭 - INTEGER(0,1)

要找到开放式商店是微不足道的,但您还需要检查是否有覆盖时间:

SELECT Shop
FROM OverrideHours
WHERE OverrideStartDate <= NOW()
AND OverrideEndDate >= NOW()
AND DayOfWeek = WEEKDAY(NOW())

如果有任何记录返回,那些商店有交替的时间或关闭.

你可以在这里做一些不错的SQL-fu,但这给你提供了基础知识.

编辑

我没有测试过这个,但这应该让你接近:

SELECT Normal.Shop
FROM Normal
LEFT JOIN Override
ON Normal.Shop = Override.Shop
AND Normal.DayOfWeek = Override.DayOfWeek
AND NOW() BETWEEN Override.OverrideStartDate AND Override.OverrideEndDate
WHERE Normal.DayOfWeek = WEEKDAY(NOW())
AND ((Override.Shop IS NULL AND TIME(NOW()) BETWEEN Normal.OpenTime AND Normal.CloseTime)
 OR  (Override.Shop IS NOT NULL AND Override.Closed <> 1 AND TIME(NOW()) BETWEEN Override.AltOpenTime AND Override.AltCloseTime))

编辑

至于效率,从某种意义上来说,它只需要对MySQL进行一次调用就很有效,如果它通过网络通常是一个瓶颈.您必须测试并确定这是否符合您的规格.如果没有,你可能会玩一些指数.

编辑

测试.没有完成测试,但有些.

mysql> select * from Normal;
+------+-----------+----------+-----------+
| Shop | DayOfWeek | OpenTime | CloseTime |
+------+-----------+----------+-----------+
|    1 |         1 | 09:00:00 | 17:00:00  | 
|    1 |         5 | 09:00:00 | 16:00:00  | 
|    2 |         1 | 09:00:00 | 17:00:00  | 
|    2 |         5 | 09:00:00 | 17:00:00  | 
+------+-----------+----------+-----------+
4 rows in set (0.01 sec)

mysql> select * from Override;
+------+-------------------+-----------------+-----------+-------------+--------------+--------+
| Shop | OverrideStartDate | OverrideEndDate | DayOfWeek | AltOpenTime | AltCloseTime | Closed |
+------+-------------------+-----------------+-----------+-------------+--------------+--------+
|    2 | 2010-12-01        | 2010-12-31      |         1 | 09:00:00    | 18:00:00     |      0 | 
|    2 | 2010-12-01        | 2010-12-31      |         5 | 09:00:00    | 18:00:00     |      0 | 
|    1 | 2010-12-01        | 2010-12-31      |         1 | 09:00:00    | 17:00:00     |      1 | 
+------+-------------------+-----------------+-----------+-------------+--------------+--------+
3 rows in set (0.00 sec)

mysql> SET @whenever = TIMESTAMP('2010-11-23 16:05');
Query OK, 0 rows affected (0.00 sec)

mysql> SELECT WEEKDAY(@whenever);
+--------------------+
| WEEKDAY(@whenever) |
+--------------------+
|                  1 | 
+--------------------+
1 row in set (0.00 sec)

mysql> SELECT Normal.Shop FROM Normal LEFT JOIN Override ON Normal.Shop = Override.Shop AND Normal.DayOfWeek = Override.DayOfWeek AND @whenever BETWEEN Override.OverrideStartDate AND Override.OverrideEndDate WHERE Normal.DayOfWeek = WEEKDAY(@whenever) AND ((Override.Shop IS NULL AND TIME(@whenever) BETWEEN Normal.OpenTime AND Normal.CloseTime)  OR  (Override.Shop IS NOT NULL AND Override.Closed <> 1 AND TIME(@whenever) BETWEEN Override.AltOpenTime AND Override.AltCloseTime));
+------+
| Shop |
+------+
|    1 | 
|    2 | 
+------+
2 rows in set (0.00 sec)

mysql> SET @whenever = TIMESTAMP('2010-11-23 17:05');
Query OK, 0 rows affected (0.00 sec)

mysql> SELECT Normal.Shop FROM Normal LEFT JOIN Override ON Normal.Shop = Override.Shop AND Normal.DayOfWeek = Override.DayOfWeek AND @whenever BETWEEN Override.OverrideStartDate AND Override.OverrideEndDate WHERE Normal.DayOfWeek = WEEKDAY(@whenever) AND ((Override.Shop IS NULL AND TIME(@whenever) BETWEEN Normal.OpenTime AND Normal.CloseTime)  OR  (Override.Shop IS NOT NULL AND Override.Closed <> 1 AND TIME(@whenever) BETWEEN Override.AltOpenTime AND Override.AltCloseTime));
Empty set (0.01 sec)

mysql> SET @whenever = TIMESTAMP('2010-12-25 16:05');
Query OK, 0 rows affected (0.00 sec)

mysql> SELECT Normal.Shop FROM Normal LEFT JOIN Override ON Normal.Shop = Override.Shop AND Normal.DayOfWeek = Override.DayOfWeek AND @whenever BETWEEN Override.OverrideStartDate AND Override.OverrideEndDate WHERE Normal.DayOfWeek = WEEKDAY(@whenever) AND ((Override.Shop IS NULL AND TIME(@whenever) BETWEEN Normal.OpenTime AND Normal.CloseTime)  OR  (Override.Shop IS NOT NULL AND Override.Closed <> 1 AND TIME(@whenever) BETWEEN Override.AltOpenTime AND Override.AltCloseTime));
+------+
| Shop |
+------+
|    2 | 
+------+
1 row in set (0.00 sec)

mysql> SET @whenever = TIMESTAMP('2010-11-23 17:05');
Query OK, 0 rows affected (0.00 sec)

mysql> SELECT WEEKDAY(@whenever);
+--------------------+
| WEEKDAY(@whenever) |
+--------------------+
|                  1 | 
+--------------------+
1 row in set (0.00 sec)

mysql> SELECT Normal.Shop FROM Normal LEFT JOIN Override ON Normal.Shop = Override.Shop AND Normal.DayOfWeek = Override.DayOfWeek AND @whenever BETWEEN Override.OverrideStartDate AND Override.OverrideEndDate WHERE Normal.DayOfWeek = WEEKDAY(@whenever) AND ((Override.Shop IS NULL AND TIME(@whenever) BETWEEN Normal.OpenTime AND Normal.CloseTime)  OR  (Override.Shop IS NOT NULL AND Override.Closed <> 1 AND TIME(@whenever) BETWEEN Override.AltOpenTime AND Override.AltCloseTime));
Empty set (0.00 sec)

Answer 2

让我们考虑每周的所有营业时间都是一样的.那么下表怎么样:

• shop_id - INTEGER(或商店的任何唯一标识符)
• week_day - INTEGER(0 =星期一 - 6 =星期日)
• opens_at - TIME(使用您当地的时区)
• closes_at - TIME(使用您当地的时区)

为所识别的商店制作一张桌子shop_id,然后插入营业时间,即:

• 1,0:8:00,17:00
• ...
• 1,5,8:00,12:00
• 2,0,7:30,12:30
• 2,0,13:30,17:30
• 2,1:7:30,12:30
• 2,1,13:30,17:30
• ...

然后SELECT:

SELECT shop_id
FROM opening_hours
WHERE WEEKDAY(NOW()) = week_day
AND TIME(NOW()) BETWEEN opens_at AND closes_at