DO $$
BEGIN
    IF to_regclass('sales_orders_p') IS NULL THEN
        EXECUTE $q$
        CREATE TABLE sales_orders_p (
            LIKE sales_orders INCLUDING ALL
        ) PARTITION BY RANGE (order_date)
        $q$;
    END IF;

    IF to_regclass('purchase_orders_p') IS NULL THEN
        EXECUTE $q$
        CREATE TABLE purchase_orders_p (
            LIKE purchase_orders INCLUDING ALL
        ) PARTITION BY RANGE (order_date)
        $q$;
    END IF;
END $$;

DO $$
DECLARE
    d date := date_trunc('month', now())::date;
    next_d date := (date_trunc('month', now()) + interval '1 month')::date;
    part_name text;
BEGIN
    part_name := format('sales_orders_p_%s', to_char(d, 'YYYYMM'));
    EXECUTE format(
        'CREATE TABLE IF NOT EXISTS %I PARTITION OF sales_orders_p FOR VALUES FROM (%L) TO (%L)',
        part_name, d, next_d
    );

    part_name := format('purchase_orders_p_%s', to_char(d, 'YYYYMM'));
    EXECUTE format(
        'CREATE TABLE IF NOT EXISTS %I PARTITION OF purchase_orders_p FOR VALUES FROM (%L) TO (%L)',
        part_name, d, next_d
    );
END $$;