Question

Given the 2 tables below, show only the activity times when the product was not offline. Keep in mind that this is a small sample of data. There will be multiple products in the activity table and multiple timestamps in the offline table.

The goal is to output when the product was online. so given the data below, I need a query that will return : rows 3,6,7 – these are the timestamps when the product was online.

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)

Answer 1

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')
        ,(1, '2011-04-13 02:00:00 AM')
        ,(1, '2011-04-13 03:00:00 AM')
        ,(1, '2011-04-13 04:00:00 AM')
        ,(1, '2011-04-13 05:00:00 AM')
        ,(1, '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 01:00:00 AM')
        ,(1, '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

Don’t have a mysql server setup at home to test it but if the AM doesnt work, then 12 AM is 00:00:00 so the first entry on the activity table should be

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

and the first entry for the offline table should be

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

tested this on my sql server and here is the output:

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