mysql - 需要优化 mysql 更新选择查询

Question

我有桌子subcategory和listing_category. listin_category表有不同的记录，其中包括subcategory和category。我想要的是在我的表中找到所有subcategory特定category说类别 = 3的计数listing_Category并在表中更新它subcategory。我想做什么

UPDATE `subcategories` SET total_count = ( SELECT count( * )
FROM `listings_category`
WHERE category =3 and subcategory IN (subcategories.id)
WHERE category_id =3 and id=subcategories.id

我在制作数组时遇到问题subcategories.id。任何帮助将不胜感激。如果有人建议更优化的查询，那就太好了。提前致谢

Answer 1

我自己解决了：）我想知道为什么人们对有意义的问题投反对票。这是解决方案。

update subcategories, 
       (
         SELECT subcategory,count(subcategory) as count 
           FROM `listings_category` 
          group by subcategory
       ) sb  
  SET subcategories.total_count = sb.count 
where subcategories.id = sb.subcategory