text: -- TABLE "users" --
  CREATE TABLE IF NOT EXISTS "users" (
    "id"        INT PRIMARY KEY,
    "username"  TEXT,
    "firstname" TEXT,
    "lastname"  TEXT,
    "state"     INT DEFAULT 0 NOT NULL
  );
  
  CREATE TABLE IF NOT EXISTS "insta_users" (
    "username"  TEXT PRIMARY KEY,
    "followers" INT,
    "following" INT
  );
  
  CREATE TABLE IF NOT EXISTS "subscriptions" (
    "user_id"        INT PRIMARY KEY REFERENCES "users" ("id"),
    "insta_username" TEXT NOT NULL REFERENCES "insta_users" ("username")
  );
  
  CREATE TYPE "group" AS ENUM('following', 'followers');
  
  CREATE TABLE IF NOT EXISTS "following_followers" (
    "username"       TEXT,
    "fullname"       TEXT,
    "URL"            TEXT,
    "refer_username" TEXT NOT NULL REFERENCES "insta_users" ("username"),
    "group_type"     "group"
  );
  