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  1. Prepare
  2. SQL
  3. Basic Join
  4. Ollivander's Inventory
  5. Discussions

Ollivander's Inventory

  • decimal_simplex
     + 7 comments

    I think you're doing the sub-query for every row in the result set though.

    If you do like this instead, you only run the sub query once, when performing the join:

    select wands.id, min_prices.age, wands.coins_needed, wands.power
from wands
inner join (select wands.code, wands.power, min(wands_property.age) as age, min(wands.coins_needed) as min_price
            from wands
            inner join wands_property
            on wands.code = wands_property.code
            where wands_property.is_evil = 0
            group by wands.code, wands.power) min_prices
on wands.code = min_prices.code
   and wands.power = min_prices.power
   and wands.coins_needed = min_prices.min_price
order by wands.power desc, min_prices.age desc