CREATE TABLE order_items
(
    order_item_id BIGSERIAL PRIMARY KEY,
    order_id      INTEGER REFERENCES orders (id),
    item_id       INTEGER,
    item_type     VARCHAR,
    price         DECIMAL   NOT NULL,
    qty           INTEGER,
    created_at    TIMESTAMP NOT NULL DEFAULT NOW(),
    updated_at    TIMESTAMP NOT NULL DEFAULT NOW(),
    created_by    INTEGER,
    updated_by    INTEGER
);