ok so i have this query
好的,所以我有这个查询
select ss.system_step_id, ss.step_number, cd.name, ssp.system_step_product_id, p.cost, ssp.class_id from system_step ss
join system as s on s.system_id=ss.system_id
join category_description as cd on cd.category_id=ss.sub_category_id
join system_step_product as ssp on ss.system_step_id=ssp.system_step_id
join product as p on p.product_id=ssp.product_id where s.system_id = 41
order by ss.step_number, ssp.class_id;
which yields this result
7 1 Screens 808 115.0000 1
7 1 Screens 809 381.9000 2
7 1 Screens 810 441.9000 3
8 2 Printers 811 112.3200 1
8 2 Printers 812 201.0400 2
8 2 Printers 813 202.8700 3
9 3 Cash Drawers 814 135.7000 1
9 3 Cash Drawers 815 86.5400 2
9 3 Cash Drawers 816 135.7000 3
sel