MySQL填充摘要報告中的空白月份。 （還有全程的3/4）

Question

這個問題從如下操作：MySQL Number of Days inside a DateRange, inside a month (Booking Table)

我有下列數據的表：

CREATE TABLE IF NOT EXISTS `bookingdata` (
`idBookingData` int(11) NOT NULL AUTO_INCREMENT, 
`PropertyID` int(10) NOT NULL, 
`Checkin` date DEFAULT NULL, 
`Checkout` date DEFAULT NULL, 
`Rent` decimal(10,2) DEFAULT NULL, 
`BookingID` int(11) DEFAULT NULL, 
PRIMARY KEY (`idBookingData`), 
UNIQUE KEY `idBookingData_UNIQUE` (`idBookingData`) 
) ENGINE=InnoDB DEFAULT CHARSET=latin1 AUTO_INCREMENT=10472 ; 

INSERT INTO `bookingdata` (`idBookingData`, `PropertyID`, `Checkin`, `Checkout`, `Rent`, `BookingID`) VALUES 
(5148, 2, '2011-07-02', '2011-07-05', 1105.00, 10612), 
(5149, 2, '2011-07-05', '2011-07-13', 2155.00, 10184), 
(5151, 2, '2011-07-14', '2011-07-17', 1105.00, 11102), 
(5153, 2, '2011-07-22', '2011-07-24', 930.00, 14256), 
(5154, 2, '2011-07-24', '2011-08-04', 1832.73, 9216), 
(5907, 2, '2011-07-24', '2011-08-04', 687.27, 9216), 
(5910, 2, '2011-08-11', '2011-08-14', 1140.00, 13633), 
(5911, 2, '2011-08-15', '2011-08-16', 380.00, 17770), 
(5915, 2, '2011-08-25', '2011-08-29', 1350.00, 17719), 
(5916, 2, '2011-08-30', '2011-09-01', 740.00, 16813); 

然後，我有這樣的SQL查詢：

SELECT 
    YEAR(month.d), 
    MONTHNAME(month.d), 
    IFNULL(SUM(
      DATEDIFF(LEAST(Checkout, LAST_DAY(month.d)), GREATEST(Checkin, month.d)) 
    ),'0') AS Days 
FROM bookingdata 
RIGHT JOIN (
     SELECT 20110101 AS d 
     UNION ALL SELECT 20110201 UNION ALL SELECT 20110301 
     UNION ALL SELECT 20110401 UNION ALL SELECT 20110501 
     UNION ALL SELECT 20110601 UNION ALL SELECT 20110701 
     UNION ALL SELECT 20110801 UNION ALL SELECT 20110901 
     UNION ALL SELECT 20111001 UNION ALL SELECT 20111101 
     UNION ALL SELECT 20111201 
     ) AS month ON (
      Checkin BETWEEN month.d AND LAST_DAY(month.d) OR month.d BETWEEN Checkin AND Checkout 
     ) 
WHERE PropertyID = "Mount Olive" 
GROUP BY month.d 

，並輸出以下內容：

+-------------+-------------------+------+ 
|YEAR(MONTH.D)| MONTHNAME(MONTH.D)| DAYS | 
+-------------+-------------------+------+ 
|2011   | July    | 30 | 
|2011   | August   | 15 | 
|2011   | September   | 0 | 
+-------------+-------------------+------+ 

雖然我想它創建以下（加襯空值）：

+-------------+-------------------+------+ 
|YEAR(MONTH.D)| MONTHNAME(MONTH.D)| DAYS | 
+-------------+-------------------+------+ 
|2011   | January   | 0 | 
|2011   | Feburary   | 0 | 
|2011   | March    | 0 | 
|2011   | April    | 0 | 
|2011   | May    | 0 | 
|2011   | June    | 0 | 
|2011   | July    | 30 | 
|2011   | August   | 15 | 
|2011   | September   | 0 | 
|2011   | October   | 0 | 
|2011   | Novemeber   | 0 | 
|2011   | December   | 0 | 
+-------------+-------------------+------+ 

什麼我需要添加，使其做到這一點？ 它在SQL小提琴上：http://sqlfiddle.com/#!2/c6bdc/2/0

Answer 1

它正確連接 - 正確的連接是完全正確的。問題是你正在篩選出你的結果。在右側（月份）與任何左側（預訂）不匹配的行上，左側的字段（包括propertyId）將爲NULL。 NULL不是「2」或「Mount Olive」，因此該行被排除。

當檢查屬性ID，使用IFNULL/COALESCE：

WHERE COALESCE(PropertyID, "Mount Olive") = "Mount Olive" 

或者使病情化合物： WHERE物業ID爲NULL或物業ID = 「橄欖山」

小提琴： http://sqlfiddle.com/#!2/c6bdc/4/0