with sessions_with_adsas (selectp.customer_id,p.session_id,p.start_time,p.end_time,a.timestampas ts,a.ad_id

from Playback p

inner join Ads a

onp.customer_id=a.customer_idand

a.timestamp betweenp.start_timeandp.end_time)

select distinct(session_id)

from (select distinct(session_id)from Playback)

where session_id notin (select distinct(session_id)from sessions_with_ads)

| 2072|[The Winner University](https://leetcode.com/problems/the-winner-university/)|[Solution](https://github.com/fishercoder1534/Leetcode/blob/master/database/_2072.sql)|| Easy|

| 2026|[Low-Quality Problems](https://leetcode.com/problems/low-quality-problems/)|[Solution](https://github.com/fishercoder1534/Leetcode/blob/master/database/_2026.sql)|| Easy|

| 1978|[Employees Whose Manager Left the Company](https://leetcode.com/problems/employees-whose-manager-left-the-company/)|[Solution](https://github.com/fishercoder1534/Leetcode/blob/master/database/_1978.sql)|| Easy|

| 1809|[Ad-Free Sessions](https://leetcode.com/problems/ad-free-sessions/)|[Solution](https://github.com/fishercoder1534/Leetcode/blob/master/database/_1809.sql)|| Easy|

| 1795|[Rearrange Products Table](https://leetcode.com/problems/rearrange-products-table/)|[Solution](https://github.com/fishercoder1534/Leetcode/blob/master/database/_1795.sql)|| Easy|

| 1789|[Primary Department for Each Employee](https://leetcode.com/problems/primary-department-for-each-employee/)|[Solution](https://github.com/fishercoder1534/Leetcode/blob/master/database/_1789.sql)|| Easy|

| 1757|[Recyclable and Low Fat Products](https://leetcode.com/problems/recyclable-and-low-fat-products/)|[Solution](https://github.com/fishercoder1534/Leetcode/blob/master/database/_1757.sql)|| Easy|