WRITE RELATIONAL ALGEBRA

1-list down the channel id's whose name have been changed twice or more than that.

select channel_id,count(*) from channel_log group by channel_id having count(*)>=2;

2- which videos have the upload time at 2017?

select title,upload_timestamp from video where upload_timestamp between '2017-01-01' and '2017-12-31';

3- List down the videos watched completely

select a.title from video a inner join visualization b on a.id=b.video_id where b.watched_entire_video='true';