Bring your SQL schema

-- E-commerce order management schema
CREATE TABLE customers (
  id            BIGSERIAL PRIMARY KEY,
  email         VARCHAR(255) UNIQUE NOT NULL,
  full_name     VARCHAR(255) NOT NULL,
  created_at    TIMESTAMPTZ DEFAULT now()
);
 
CREATE TABLE products (
  id            BIGSERIAL PRIMARY KEY,
  sku           VARCHAR(64) UNIQUE NOT NULL,
  name          VARCHAR(255) NOT NULL,
  price_cents   INTEGER NOT NULL CHECK (price_cents >= 0),
  inventory     INTEGER NOT NULL DEFAULT 0
);
 
CREATE TABLE orders (
  id            BIGSERIAL PRIMARY KEY,
  customer_id   BIGINT NOT NULL REFERENCES customers(id),
  status        VARCHAR(32) NOT NULL DEFAULT 'pending',
  total_cents   INTEGER NOT NULL,
  placed_at     TIMESTAMPTZ DEFAULT now()
);
 
CREATE TABLE order_items (
  id            BIGSERIAL PRIMARY KEY,
  order_id      BIGINT NOT NULL REFERENCES orders(id),
  product_id    BIGINT NOT NULL REFERENCES products(id),
  quantity      INTEGER NOT NULL CHECK (quantity > 0),
  unit_cents    INTEGER NOT NULL
);
 
CREATE INDEX idx_orders_customer ON orders(customer_id);
CREATE INDEX idx_items_order ON order_items(order_id);
CREATE INDEX idx_items_product ON order_items(product_id);
 
CREATE TRIGGER trg_update_inventory
AFTER INSERT ON order_items
FOR EACH ROW EXECUTE FUNCTION decrement_inventory();
 
CREATE TRIGGER trg_order_total
AFTER INSERT OR UPDATE ON order_items
FOR EACH ROW EXECUTE FUNCTION recompute_order_total();