Mysql子查询太慢，查询销售号

Question

I have three table: one: table order_info

ordre_id     int
add_time     int

two: table order_goods

id           int
goods_id     int
order_id     int
sale_number  int

three: table goods

goods_id     int 
goods_name   varchar

Now I want query goods sale total number and order by this number, and when goods has no sale number, show it with zero. I use subquery, but it's too slowly, sql is like:

SELECT t.* 
FROM goods AS tg 
LEFT JOIN (
    SELECT SUM(og.goods_number) AS total_num, g.goods_id, g.goods_name 
    FROM order_info oi 
    LEFT JOIN order_goods AS og     ON oi.order_id=og.order_id 
    LEFT JOIN goods AS g            ON g.goods_id=og.goods_id 
    WHERE oi.add_time>1415635200 
) AS t          ON t.goods_id=tg.goods_id 
ORDER BY t.total_num DESC;

Can you have some goods idea? Thanks!

Answer 1

Why not just remove the outer query part and run a

select 
    SUM(og.goods_number) AS total_num, 
    g.goods_id, 
    g.goods_name 
from 
    order_info oi 
left join order_goods AS og on oi.order_id=og.order_id 
left join goods AS g on g.goods_id=og.goods_id 
right join goods as g2 on g2.goods_id=og.goods_id 
where  oi.add_time > 1415635200 

? What Indices have you set on your tables?

Answer 2

you don't need outer query you can use GROUP BY instead.

select SUM(og.goods_number) AS total_num, 
       g.goods_id, 
       g.goods_name
from order_info oi 
left join order_goods AS og 
on oi.order_id=og.order_id 
left join goods AS g 
on g.goods_id=og.goods_id 
where  oi.add_time>1415635200 
group by g.goods_id, g.goods_name
order by total_num desc

Answer 3

if i read your questions, you need total sales all goods. try this one :

Select  g.goods_id, g.goods_name, IsNull(SUM(og.goods_number), 0) as total_num
From goods g
Left Join order_goods og
    On og.goods_id = g.goods_id
Left Join order_info oi
    On oi.order_id = og.order_id
WHERE oi.add_time>1415635200
Group By g.goods_id, g.goods_name
Order By total_num desc

i just confuse with your query actually. "goods_number" column comes from where ? what is meant is "sale_number" column ?