Mysql子查詢

Question

我需要幫助來編寫子查詢。

我有一個包含精選文章和非精選文章的類別的文章表。

我想挑選4個最新的精選文章，這些精選文章不屬於前6個最新的精選文章，無論其類別如何。這是我做了什麼

select title 
from node 
where nid NOT IN(select nid from node order by date limit 6) 
order by date 
limit 4 

Answer 1

假設了一下這裏，但你的意思是這樣的嗎？

select title 
from node 
where nid NOT IN(select nid from node where featured = 1 order by date desc limit 6) 
and featured = 1 
and category = ... 
order by date desc 
limit 4 

Answer 2

我記得，LIMIT尚不支持在IN()子查詢。相反，您需要針對子查詢LEFT JOIN並在子查詢中查找NULL s：

SELECT title 
FROM 
    node 
    LEFT JOIN (SELECT nid FROM node ORDER BY date LIMIT 6) nids ON node.nid = nids.nid 
WHERE 
    nids.nid IS NULL 
    AND node.category = 'some category' 
ORDER BY date 
LIMIT 4