How to UPDATE and set values to a column in a sub-query on the same table

I'm having trouble getting this SQL to work. Basically I want to UPDATE the column sort_order and set it to the parents_sort_order which is selected by a subquery on the same table. Here's my SELECT query showing the data I need....

SELECT p.id,p.sort_order,p.parent_id, (
  SELECT `sort_order` AS parent_sor开发者_如何学Pythont_order
  FROM `product`
  WHERE id = p.parent_id
)
FROM  `product` p
WHERE p.dealer_id !=0
AND p.vendor_id >100

Thanks!

Join version of your select:

SELECT p.id,p.sort_order,p.parent_id, b.sort_order as parent_sort_order
FROM  `product` p join `product` b
on p.id = b.parent_id
WHERE p.dealer_id !=0
AND p.vendor_id >100

Update Option 1:

update product a, product b set a.sort_order = b.parent_sort_order
where a.id = b.parent_id
and a.dealer_id !=0
and a.vendor_id > 100

Update Option 2:

update product a left join product b on a.id = b.parent_id 
set a.sort_order = b.parent_sort_order
where a.dealer_id !=0
and a.vendor_id > 100