sql挑战-使用多个引用来限制日期

问题描述

| 根据以下2个表格，仅显示产品不离线时的活动时间。请记住，这只是一小部分数据。活动表中将有多个产品，离线表中将有多个时间戳。 目标是在产品在线时输出。因此，鉴于以下数据，我需要一个查询，该查询将返回：第3、6、7行-这些是产品在线时的时间戳记。

MysqL> select * from activity;
+------------+---------------------+
| product_id | activity_date       |
+------------+---------------------+
|          1 | 2011-04-13 12:00:00 |
|          1 | 2011-04-13 01:00:00 |
|          1 | 2011-04-13 02:00:00 |
|          1 | 2011-04-13 03:00:00 |
|          1 | 2011-04-13 04:00:00 |
|          1 | 2011-04-13 05:00:00 |
|          1 | 2011-04-13 06:00:00 |
+------------+---------------------+
7 rows in set (0.01 sec)

MysqL> select * from offline
+------------+---------------------+---------------------+
| product_id | offline_start       | offline_end         |
+------------+---------------------+---------------------+
|          1 | 2011-04-13 12:00:00 | 2011-04-13 01:00:00 |
|          1 | 2011-04-13 03:00:00 | 2011-04-13 04:00:00 |
+------------+---------------------+---------------------+
2 rows in set (0.01 sec)

    

解决方法

create table activity
(
    product_id int,activity_date datetime
);

create table [offline]
(
    product_id int,offline_start datetime,offline_end datetime
);

insert into activity(product_id,activity_date) 
  values (1,\'2011-04-13 12:00:00 AM\'),(1,\'2011-04-13 01:00:00 AM\'),\'2011-04-13 02:00:00 AM\'),\'2011-04-13 03:00:00 AM\'),\'2011-04-13 04:00:00 AM\'),\'2011-04-13 05:00:00 AM\'),\'2011-04-13 06:00:00 AM\');

insert into [offline](product_id,offline_start,offline_end) 
  values (1,\'2011-04-13 12:00:00 AM\',\'2011-04-13 03:00:00 AM\',\'2011-04-13 04:00:00 AM\');        

select  a.*
from    activity a
        left join offline o
            on a.product_id = o.product_id
            and a.activity_date between o.offline_start and o.offline_end
where   o.product_id IS NULL

在家中没有用于测试的mysql服务器设置，但如果AM不起作用，则12 AM为00:00:00，因此活动表上的第一个条目应为

1,\'2011-04-13 00:00:00\'

离线表的第一个条目应该是

1,\'2011-04-13 00:00:00\',\'2011-04-13 01:00:00\'

在我的sql服务器上测试了它，这是输出：

product_id  activity_date
1   2011-04-13 02:00:00.000
1   2011-04-13 05:00:00.000
1   2011-04-13 06:00:00.000