DELIMITER $$
DROP PROCEDURE IF EXISTS InsertProductLinks$$
CREATE PROCEDURE InsertProductLinks()
  BEGIN
    DECLARE min_pg INT;
    DECLARE max_pg INT;
    DECLARE pg INT;
    DECLARE cat INT;
    SELECT min_pg = min(id), max_pg = max(id) FROM product_landing_pages;
    SELECT pg = min_pg, cat = pn_category_id FROM product_landing_pages WHERE id = min_pg;
    WHILE pg <= max_pg
      /* get next category # */
      select cat = pn_category_id from product_landing_pages where id = pg;
      /* delete existing records/parts per current category */
      delete apto...part_number_landing_links where pn_category_id = @cat;
      /* insert 4 random parts per current category */
      insert  into apto...part_number_landing_links(part_number_id, product_landing_page_id, pn_category_id);
      select pn.id as part_number_id, pg as product_landing_page_id, cat as pn_category_id from product_price_upd
      join part_cat
        on partnumber = part_cat.part
        and mfgcode = part_cat.line
      join pn_categories
        on left(grp, 45) = left(name, 45)
        and pn_categories.id = @cat
      join part_numbers pn
        on part_cat.line = line_code
        and part = pn.number;
      where qty_available > 0
      /* increment page # */
      set @pg = @pg+1;
    END WHILE;
  END$$
DELIMITER;