存儲工作時間和高效查詢的最佳方式

Question

我打算存儲商店的工作時間。我想知道什麼可能是工作時間領域的最佳建模，以便我可以非常有效地獲得當前開放/關閉商店的列表。

Answer 1

要存儲的正常運行時間，你將需要存儲多個含有記錄：

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

我假設例如在節假日每家店鋪已經減少小時，或有工廠停工，所以你也需要存儲一些替代記錄：

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

找到空位的商店是微不足道的，但你還需要檢查是否有越權小時：

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

如果有是否有任何記錄被返回，這些商店有交替時間或關閉。

可能有一些很好的SQL-fu可以在這裏做，但是這給了你基本的東西。

編輯

我沒有測試過這一點，但是這應該讓你接近：

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)) 

編輯

至於效率，它是在這個意義上是有效的你只需要打一個電話給MySQL，如果它是通過網絡的話，這通常是一個瓶頸。您必須測試並查看這是否符合您的規格。如果沒有，你可能會玩一些指數。

編輯

測試。不完整的測試，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

讓我們考慮每週的開放時間都是一樣的。那麼，關於下表：

• shop_id - INTEGER（或車間的任何唯一標識符）
• WEEK_DAY - INTEGER（0 =週一 - 6 =週日）
• opens_at - 時間（使用本地時區）
• closes_at - 時間（使用本地時區）

做一個表，通過shop_id標識的商店，然後插入的開放時間，即：

• 1,0，8點，17：00
• ...
• 1，5，8點，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
• ...

，然後選擇：

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