jaanhio / nba_stats

[node,json,sql]

SQL Clauses & Aggregation

Part 1

Create a database called nba_db.

createdb nba_db -U USERNAME

I've created the schema for a table called players in the file tables.sql. The schema includes an id, name, age, team, games, and points.

Run the tables.sql file for your nba_db by typingpsql -d nba_db -f tables.sql into your terminal (not in psql). This will create the players table in your nba_db.

Part 2

Create a node script (perhaps called populate-db.js) to load your data from the players.json file into your database.

Load the pg library:

yarn init
yarn add pg

Load your jsonfile library

yarn add jsonfile

Require the libraries

const pg = require('pg');
const jsonfile = require('jsonfile');

// set all of the configuration in an object
const configs = {
  user: 'akira',
  host: '127.0.0.1',
  database: 'pokemons',
  port: 5432,
};

// create a new instance of the client
const client = new pg.Client(configs);

Use jsonfile to get the player records

jsonfile.readFile('players.json', (err, obj) => {
  if (err) console.error(err);
  // obj is all the player records
  // what now?
});

Hint: does this need to be nested somewhere? Or not? What is the true order of operations?

// start using your client

client.connect((err) => {

  if (err) {
    console.log('error', err.message);
  }

  // your queries go here
  let queryString = '';

  // your dynamic values go here
  let values = [];

  client.query(queryString, values, (err, res) => {
    if (err) {
      console.log('query error', err.message);
    } else {
      console.log('result', res.rows[0]);
    }
    
    // the last query you make, close the connection.
    client.end();
  });
});

Run the populate-db.js program ONCE to populate the database. It should read in the information from the players.json textfile and populates your database.

The data is structured with the following keys:name,age,team,games,points

** games is games played during the season and points is total points scored over the course of the season.

Part 3

Figure out the appropriate SQL commands to find out the following, and keep track of them in the file called sql_commands.txt

1. All columns for all players from the New York Knicks (NYK)
2. All columns for all players from the Indiana Packers (IND) who are under 26 years old
3. All columns for all players, ordered from least points scored to most points scored
4. Name and Points per game (points/games), for the players with the top 20 points per game
5. The average age for all players
6. The average age for all players on the Oklahoma City Thunder (OKC)
7. The average age for all players who played more than 40 games
8. The team and total points scored from all players on that team (team points), ordered from most team points to least

Further

1. Age and the average points per game for that age, ordered from youngest to oldest
2. Team and the the number of players who score above 12 points per game on that team, ordered from most to least

Further

Write the node.js code that executes each SQL statement.