Question

我正在尝试从具有随机日期范围的表中进行选择。像

这样的东西

SELECT * FROM my_table WHERE timestamp 
BETWEEN <random_date> AND <the_same_random_date> - INTERVAL 1 DAY

那样我应该选择一个随机日期1天的间隔。有什么建议吗？

更新：因此，随机查询可能与以下查询具有相同的效果：

SELECT * FROM my_table WHERE timestamp 
BETWEEN '2011-08-05 00:00' AND '2011-08-05 00:00' - INTERVAL 1 DAY

SELECT * FROM my_table WHERE timestamp 
BETWEEN '2011-08-12 14:30' AND '2011-08-12 14:30' - INTERVAL 1 DAY

SELECT * FROM my_table WHERE timestamp 
BETWEEN '2011-05-11 06:15' AND '2011-05-11 06:15' - INTERVAL 1 DAY

SELECT * FROM my_table WHERE timestamp 
BETWEEN '2011-03-03 21:11' AND '2011-03-03 21:11' - INTERVAL 1 DAY

Answer 1

SELECT * 
FROM 
    my_table
    CROSS JOIN (SELECT FROM_UNIXTIME(RAND() * 2147483647) random_date) rd
WHERE 
    timestamp BETWEEN (rd.random_date - INTERVAL 1 DAY) AND rd.random_date

Answer 2

使用BETWEEN时，必须先使用较小（较早）的值。例如，而不是

SELECT * FROM my_table WHERE timestamp 
BETWEEN '2011-08-05 00:00' AND '2011-08-05 00:00' - INTERVAL 1 DAY

你想要使用

SELECT * FROM my_table WHERE timestamp 
BETWEEN '2011-08-05 00:00' - INTERVAL 1 DAY AND '2011-08-05 00:00'

您是否在询问如何使用MySQL生成这些随机日期？或者你只是想知道为什么你的查询不起作用？如果你想要生成随机日期，那么Karolis的答案对你来说应该是很好的。

选择随机日期范围

2 个答案: