Per memorizzare le normali ore di funzionamento, dovresti memorizzare un numero di record contenenti:
- Acquista - INTEGER
- DayOfWeek - INTEGER (0-6)
- OpenTime - ORA
- Ora di chiusura - ORA
Presumo, ad esempio, che ogni negozio abbia orari ridotti durante le festività nazionali, o abbia chiusure di impianti, quindi dovresti anche memorizzare alcuni record di override:
- Acquista - INTEGER
- Sostituisci DataInizio - DATA
- SostituisciEndDate - DATA
- DayOfWeek - INTEGER (0-6)
- AltOpenTime - ORA
- AltCloseTime - ORA
- Chiuso - INTEGER (0, 1)
Trovare negozi aperti è banale, ma devi anche controllare se ci sono orari di override:
SELECT Shop
FROM OverrideHours
WHERE OverrideStartDate <= NOW()
AND OverrideEndDate >= NOW()
AND DayOfWeek = WEEKDAY(NOW())
Se vengono restituiti dei record, quei negozi hanno orari alterni o sono chiusi.
Potrebbe esserci del bel SQL-fu che puoi fare qui, ma questo ti dà le basi.
MODIFICA
Non l'ho testato, ma questo dovrebbe avvicinarti:
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))
MODIFICA
Per quanto riguarda l'efficienza, è efficiente nel senso che devi solo effettuare una chiamata a MySQL che spesso è un collo di bottiglia se si trova attraverso una rete. Dovrai testare e vedere se questo funziona secondo le tue specifiche. In caso contrario, potresti giocare con alcuni indici.
MODIFICA
Test. Test non completi, ma alcuni.
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)
