存储工作时间和高效查询的最佳方式

Question

我打算存储商店的工作时间。我想知道什么可能是工作时间领域的最佳建模，以便我可以非常有效地获得当前开放/关闭商店的列表。

Answer 1

要存储的正常运行时间，你将需要存储多个含有记录：

• 店 - INTEGER
• DAYOFWEEK - INTEGER（ 0-6）
• OpenTime - TIME
• CloseTim Ë - TIME

我假设例如在节假日每家店铺已经减少小时，或有工厂停工，所以你也需要存储一些替代记录：

• 店 - INTEGER
• OverrideStartDate - DATE
• OverrideEndDate - DATE
• DAYOFWEEK - INTEGER（0-6）
• AltOpenTime - TIME
• AltCloseTime - TIME
• 封闭 - 整数（0,1）

找到空位的商店是微不足道的，但你还需要检查是否有越权小时：

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

如果有是否有任何记录被返回，这些商店有交替时间或关闭。

可能有一些很好的SQL-fu可以在这里做，但是这给了你基本的东西。

编辑

我没有测试过这一点，但是这应该让你接近：

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，它是在这个意义上是有效的你只需要打一个电话给MySQL，如果它是通过网络的话，这通常是一个瓶颈。您必须测试并查看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。不完整的测试，但一些。

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

让我们考虑每周的开放时间都是一样的。那么，关于下表：

• shop_id - INTEGER（或车间的任何唯一标识符）
• WEEK_DAY - INTEGER（0 =周一 - 6 =周日）
• opens_at - 时间（使用本地时区）
• closes_at - 时间（使用本地时区）

做一个表，通过shop_id标识的商店，然后插入的开放时间，即：

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

，然后选择：

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