特定时间范围内的重叠计数

Question

我有一个查询，我试图在数据库中查找某个时间范围内查看某项内容的次数。

这是我目前的查询：

USE DB1
SELECT DISTINCT NAME,
COUNT(*) AS COUNT
FROM LOGS
WHERE EVENT = 'Viewed'
AND TIME BETWEEN '2015-04-22 00:00:00.000' AND '2015-07-24 00:00:00.000'
GROUP BY NAME
ORDER BY COUNT DESC;

这个查询成功地告诉我在这 3 个月的范围内查看了多少次，但是当我将时间范围缩短到三个不同的查询时，该特定行从：

TIME BETWEEN '2015-04-22 00:00:00.000' AND '2015-05-22 00:00:00.000';
TIME BETWEEN '2015-05-22 00:00:00.000' AND '2015-06-22 00:00:00.000';
TIME BETWEEN '2015-06-22 00:00:00.000' AND '2015-04-24 00:00:00.000';

然后，当我将不同的值相加时，它们不相等。事实上，它们比我在三个月范围内的第一个查询中获得的行数要高得多。我假设某些值是重叠的。我怎样才能解决这个问题？我检查了我的工作，我很确定第一个查询在时间范围内给了我正确的行数，但我需要更具体的数据

Answer 1

X BETWEEN Y AND Z 

翻译成

X >= Y AND X <= Z

因此，您应该对整个范围内的期间使用不同的查询，例如：

TIME >= '2015-04-22 00:00:00.000' AND TIME < '2015-05-22 00:00:00.000';
TIME >= '2015-05-22 00:00:00.000' AND TIME < '2015-06-22 00:00:00.000';
TIME >= '2015-06-22 00:00:00.000' AND TIME <= '2015-07-24 00:00:00.000';

上一个时间段的逻辑取决于您...例如，您可以将其重新排列为：

TIME >= '2015-06-22 00:00:00.000' AND TIME < '2015-07-25 00:00:01.000';

Answer 2

col BETWEEN a AND b 被计算为a <= col <= b，因此您的时间范围内有一个重叠间隔

将这个从午夜改为午夜前一秒：

TIME BETWEEN '2015-04-22 00:00:00.000' AND '2015-04-22 23:59:59.999';
TIME BETWEEN '2015-05-22 00:00:00.000' AND '2015-05-22 23:59:59.999';
TIME BETWEEN '2015-06-22 00:00:00.000' AND '2015-04-24 23:59:59.999';

更新

试试这个：

TIME BETWEEN '2015-04-22 00:00:00' AND '2015-04-22 23:59:59';
TIME BETWEEN '2015-05-22 00:00:00' AND '2015-05-22 23:59:59';
TIME BETWEEN '2015-06-22 00:00:00' AND '2015-04-24 23:59:59';