The following lines contain the word 'select', 'insert', 'update' or 'delete':
SELECT DISTINCT msn.end_item_unit_number
INTO v_end_item_unit_number
FROM mtl_serial_numbers msn,
rcv_serials_supply rss
WHERE msn.serial_number = rss.serial_num
AND rss.shipment_line_id = p_shipment_line_id
AND msn.inventory_item_id = p_item_id;