demo.sql

CREATE TABLE customers (
    id         SERIAL PRIMARY KEY,
    name       TEXT        NOT NULL,
    email      TEXT        NOT NULL UNIQUE,
    country    TEXT        NOT NULL,
    created_at TIMESTAMPTZ NOT NULL DEFAULT now()
);

CREATE TABLE products (
    id       SERIAL PRIMARY KEY,
    name     TEXT           NOT NULL,
    category TEXT           NOT NULL,
    price    NUMERIC(10, 2) NOT NULL
);

CREATE TABLE orders (
    id          SERIAL PRIMARY KEY,
    customer_id INTEGER        NOT NULL REFERENCES customers (id),
    product_id  INTEGER        NOT NULL REFERENCES products (id),
    quantity    INTEGER        NOT NULL,
    total       NUMERIC(10, 2) NOT NULL,
    placed_at   TIMESTAMPTZ    NOT NULL DEFAULT now()
);

INSERT INTO customers (name, email, country) VALUES
    ('Alice Martin',   'alice@example.com',   'US'),
    ('Bob Silva',      'bob@example.com',     'BR'),
    ('Carla Rossi',    'carla@example.com',   'IT'),
    ('David Chen',     'david@example.com',   'CN'),
    ('Eva Müller',     'eva@example.com',     'DE');

INSERT INTO products (name, category, price) VALUES
    ('Wireless Mouse',   'Electronics',  29.99),
    ('Mechanical Keyboard', 'Electronics', 89.99),
    ('USB-C Hub',        'Electronics',  49.99),
    ('Desk Lamp',        'Office',       34.99),
    ('Notebook',         'Stationery',    4.99);

INSERT INTO orders (customer_id, product_id, quantity, total) VALUES
    (1, 2, 1,  89.99),
    (1, 3, 2,  99.98),
    (2, 1, 1,  29.99),
    (3, 4, 1,  34.99),
    (4, 5, 3,  14.97),
    (5, 1, 2,  59.98),
    (5, 2, 1,  89.99);