# $1809. 没有广告的剧集
# https://leetcode.cn/problems/ad-free-sessions/

# SQL架构
Create table If Not Exists Playback(session_id int,customer_id int,start_time int,end_time int);
Create table If Not Exists Ads (ad_id int, customer_id int, timestamp int);
Truncate table Playback;
insert into Playback (session_id, customer_id, start_time, end_time) values ('1', '1', '1', '5');
insert into Playback (session_id, customer_id, start_time, end_time) values ('2', '1', '15', '23');
insert into Playback (session_id, customer_id, start_time, end_time) values ('3', '2', '10', '12');
insert into Playback (session_id, customer_id, start_time, end_time) values ('4', '2', '17', '28');
insert into Playback (session_id, customer_id, start_time, end_time) values ('5', '2', '2', '8');
Truncate table Ads;
insert into Ads (ad_id, customer_id, timestamp) values ('1', '1', '5');
insert into Ads (ad_id, customer_id, timestamp) values ('2', '2', '17');
insert into Ads (ad_id, customer_id, timestamp) values ('3', '2', '20');

# Write your MySQL query statement below
select
    session_id
from
    Playback
where
    session_id not in (
        select
            distinct(p.session_id)
        from
            Playback p
            left join Ads a on p.customer_id = a.customer_id
        where
            p.start_time <= a.timestamp
            and a.timestamp <= p.end_time
    );

# clean-up
drop table Playback;
drop table Ads;