text: CREATE TABLE leagues (
    id serial PRIMARY KEY,
    league_name text UNIQUE NOT NULL,
    sport text NOT NULL,
    country text NOT NULL
  );
  
  CREATE TABLE teams (
    id serial PRIMARY KEY,
    league_id int NOT NULL REFERENCES leagues (id),
    team_name_full text UNIQUE NOT NULL,
    team_city text NOT NULL,
    team_mascot text NOT NULL
  );
  
  CREATE TABLE schedules (
    id serial PRIMARY KEY,
    league_id int NOT NULL REFERENCES leagues (id),
    home_team_id int NOT NULL REFERENCES teams (id),
    away_team_id int NOT NULL REFERENCES teams (id),
    season text NOT NULL,
    game_date_utc timestamp with time zone NOT NULL,
    tv_network text NOT NULL,
    national_broadcast boolean
  );
  
  CREATE TABLE users (
    id serial PRIMARY KEY,
    email_address text NOT NULL,
    sms_phone_number text NOT NULL,
    password text NOT NULL
  );
  
  CREATE TABLE alerts (
    id serial PRIMARY KEY,
    team_id int NOT NULL REFERENCES teams (id),
    user_id int NOT NULL REFERENCES users (id) ON DELETE CASCADE,
    mode text NOT NULL,
    freq text NOT NULL,
    active boolean NOT NULL
  );