How to structure nested arrays with postgresql - node.js

Question

I'm making a simple multiplayer game using postgres as a database (and node as the BE if that helps). I made the table users which contains all of the user accounts, and a table equipped, which contains all of the equipped items a user has. users has a one -> many relationship with equipped.
I'm running into the situation where I need the data from both tables structured like so:
[
{
user_id: 1,
user_data...
equipped: [
{ user_id: 1, item_data... },
...
],
},
{
user_id: 2,
user_data...
equipped: [
{ user_id: 2, item_data... },
...
],
},
]
Is there a way to get this data in a single query? Is it a good idea to get it in a single query?
EDIT: Here's my schemas
CREATE TABLE IF NOT EXISTS users (
user_id SERIAL PRIMARY KEY,
username VARCHAR(100) UNIQUE NOT NULL,
password VARCHAR(100) NOT NULL,
email VARCHAR(100) NOT NULL,
created_on TIMESTAMP NOT NULL DEFAULT NOW(),
last_login TIMESTAMP,
authenticated BOOLEAN NOT NULL DEFAULT FALSE,
reset_password_hash UUID
);
CREATE TABLE IF NOT EXISTS equipment (
equipment_id SERIAL PRIMARY KEY NOT NULL,
inventory_id INTEGER NOT NULL REFERENCES inventory (inventory_id) ON DELETE CASCADE,
user_id INTEGER NOT NULL REFERENCES users (user_id) ON DELETE CASCADE,
slot equipment_slot NOT NULL,
created_on TIMESTAMP NOT NULL DEFAULT NOW(),
CONSTRAINT only_one_item_per_slot UNIQUE (user_id, slot)
);

Answer 1

Okay so what I was looking for was closer to postgresql json aggregate, but I didn't know what to look for.
Based on my very limited SQL experience, the "classic" way to handle this would just to do a simple JOIN query on the database like so:
SELECT users.username, equipment.slot, equipment.inventory_id
FROM users
LEFT JOIN equipment ON users.user_id = equipment.user_id;
This is nice and simple, but I would need to merge these tables in my server before sending them off.
Thankfully postgres lets you aggregate rows into a JSON array, which is exactly what I needed (thanks #j-spratt). My final* query looks like:
SELECT users.username,
json_agg(json_build_object('slot', equipment.slot, 'inventory_id', equipment.inventory_id))
FROM users
LEFT JOIN equipment ON users.user_id = equipment.user_id
GROUP BY users.username;
Which returns in exactly the format I was looking for.