MySQL：BETWEEN - 查詢中的不同結果

Question

我有一個奇怪的行爲，如果有人能解釋這一點，我會很高興嗎？今天是2016年5月22日（面向未來的讀者）。

SELECT `Opened`, 
    `Milestone_Status`, 
    Year(`Opened`), 
    Month(`Opened`), 
    Count(*) As Total_Rows 
FROM Cases 
WHERE `Opened` BETWEEN (CURRENT_DATE() - INTERVAL 6 MONTH) AND (CURRENT_DATE() - INTERVAL 2 MONTH) 
GROUP BY Year(`Opened`), Month(`Opened`), `Milestone_Status`; 

結果如下：

+------------+------------------+----------------+-----------------+------------+ 
| Opened  | Milestone_Status | Year(`Opened`) | Month(`Opened`) | Total_Rows | 
+------------+------------------+----------------+-----------------+------------+ 
| 2016-12-07 | Compliant  |   2016 |    12 |   2 | 
| 2017-01-10 | Compliant  |   2017 |    1 |   6 | 
| 2017-02-23 | Closed Violation |   2017 |    2 |   1 | 
| 2017-02-27 | Compliant  |   2017 |    2 |   1 | 
| 2017-03-01 | Closed Violation |   2017 |    3 |   1 | 
| 2017-03-06 | Compliant  |   2017 |    3 |   2 | 
+------------+------------------+----------------+-----------------+------------+ 
6 rows in set (0.02 sec) 

所以，當我改變從2一個月的差異爲3，它應該顯示的線條，直到本月（ '開'）2，但..

SELECT `Opened`, 
    `Milestone_Status`, 
    Year(`Opened`), 
    Month(`Opened`), 
    Count(*) As Total_Rows 
FROM Cases WHERE `Opened` BETWEEN (CURRENT_DATE() - INTERVAL 6 MONTH) AND (CURRENT_DATE() - INTERVAL 3 MONTH) 
GROUP BY Year(`Opened`), Month(`Opened`), `Milestone_Status`; 

result: 
+------------+------------------+----------------+-----------------+------------+ 
| Opened  | Milestone_Status | Year(`Opened`) | Month(`Opened`) | Total_Rows | 
+------------+------------------+----------------+-----------------+------------+ 
| 2016-12-07 | Compliant  |   2016 |    12 |   2 | 
| 2017-01-10 | Compliant  |   2017 |    1 |   6 | 
+------------+------------------+----------------+-----------------+------------+ 
2 rows in set (0.01 sec) 

任何想法，更好的方法，請嗎？

Answer 1

所以，當我改變從2到一個月的區別3，它應該顯示直到Month（'Opened'）2的行，但是..

因爲今天是22，所以你的結果是真的。

如果您想從2開始獲得Month（'Opened'），請在月份試用。

編輯：CURRENT_DATE與DATEADD（）

實施例：3月份：DATEADD（米，-3，GETDATE（））。

希望它能幫助你。

Answer 2

不，輸出是正確的。作爲

CURRENT_DATE() - INTERVAL 3 MONTH 

是

2017年2月22日

所以你查詢變爲：

SELECT `Opened`,`Milestone_Status`,YEAR(`Opened`), MONTH(`Opened`), 
COUNT(*) AS Total_Rows 
FROM Cases WHERE `Opened` 
BETWEEN (2016-11-22) AND (2017-02-22) 
GROUP BY YEAR(`Opened`), MONTH(`Opened`), `Milestone_Status`;