Question

基本上，我想在8月到5月之间为一组给定的日期提取数据。使用between运算符可以工作，只要我没有越过年份标记（即BETWEEN 8和12工作 - BETWEEN 8和5不工作）。有没有办法提取这些数据？这是我写的SQL查询：

SELECT count(*), MONTH(DateTime)
FROM Downloads
WHERE YEAR(DateTime) BETWEEN 2009 AND 2010 AND MONTH(DateTime) BETWEEN 8 AND 5 
GROUP BY MONTH(DateTime)
ORDER BY MONTH(DateTime)"

感谢任何帮助。

谢谢，

Eric R。

Answer 1

将BETWEEN与YEAR（）和MONTH（）一起使用会破坏在该列上使用索引的任何机会。我会用：

SELECT
    COUNT(*) AS [count],
    YEAR(my_date) AS [year],
    MONTH(my_date) AS [month]
FROM
    Downloads
WHERE
    my_date >= '2009-08-01' AND
    my_date < '2010-06-01'
GROUP BY
    YEAR(my_date),
    MONTH(my_date)
ORDER BY
    YEAR(my_date), MONTH(my_date)

（我使用了my_date，因为我无法将自己引用为DateTime的列）:)）

Answer 2

SELECT count(*), MONTH(DateTime)
FROM Downloads
WHERE DateTime>'2009/8/1 00:00:00' AND datetime<'2010/6/1 00:00:00'
GROUP BY MONTH(DateTime)
ORDER BY MONTH(DateTime)

如何从跨越一学年的SQL数据库中提取数据？

2 个答案: