(a) Once we delete a user, we should delete all tweets posted by that user. Implement this functionality using a SQL trigger.

(b) Find all users who read about iPhone 11 before its launch (i.e., before Nov. 3, 2019).

(c) Find all users (uname and city) who follow at least everyone that user Donald Trump follows.

Users (uname, city, street) - you may assume that uname is unique Follows (uname1, uname 2) - user with unamel follows user with uname2 Tweets (tid, t_tittle, t_text) - tweet with tid has title t_title & content t_text User Tweets (uname, tid, ts) - user uname posted a tweet with tid at time ts Tweet Tags (tid, tag) - tweet with tid has tag in its list of tags. we would like to extract some useful information from the database and we leave this job to our database expert (you!). Use MySql or Postgresql Users (uname, city, street) - you may assume that uname is unique Follows (uname1, uname 2) - user with unamel follows user with uname2 Tweets (tid, t_tittle, t_text) - tweet with tid has title t_title & content t_text User Tweets (uname, tid, ts) - user uname posted a tweet with tid at time ts Tweet Tags (tid, tag) - tweet with tid has tag in its list of tags. we would like to extract some useful information from the database and we leave this job to our database expert (you!). Use MySql or Postgresql