question archive Hello Tutors,I need help on this CS50 SQL question, where we have to write SQL queries and statements Here is the Question: Some social networks, including Twitter and Instagram, allow one user (a "follower") to follow another user (a "followee")
Subject:ManagementPrice: Bought3
Here is the Question:
Some social networks, including Twitter and Instagram, allow one user (a "follower") to follow another user (a "followee"). Let's consider how such networks might represent data about their users. A social network might, for instance, have a SQL database with tables like the below.
CREATE TABLE users (
id INTEGER,
username TEXT UNIQUE,
name TEXT,
PRIMARY KEY(id)
);
CREATE TABLE followers (
follower_id INTEGER,
followee_id INTEGER,
FOREIGN KEY (follower_id) REFERENCES users(id),
FOREIGN KEY (followee_id) REFERENCES users(id)
);
Assume that Ileana is registered for this social network with a username of ileana, that Reese is registered with a username of reese, and that Max is registered with a username of max.
Social networks like Twitter and Instagram support asymmetric relationships: Alice might follow Bob, but that does not mean that Bob also follows Alice. Other social networks, like Facebook, support symmetric relationships as well: in order for Alice and Bob to be "friends," one of them must send a "friend request" to the other, which the other must then accept.
