我有两张桌子
question
------------------------------
qid | qname | description
------------------------------
1 ssc? blabla
2 BIE blabla
3 msc blabla
answer
----------------------------
aid | uid | qid | answered_on
-------------------------------
1 1 1 ssc means
2 2 1 ssc
-------------------------------
现在我想获得如何编写查询的未解答的问题?你能告诉任何人。
i get the result like
qid | qname
-----------
2 BIE
3 msc
答案 0 :(得分:1)
SELECT qid, qname FROM question
WHERE qid NOT IN (SELECT DISTINCT qid FROM answer)
虽然不是真正的服务器故障问题。
答案 1 :(得分:1)
select * from users as ru left join answers as ra on ru.uid=ra.uid
left join questions as rq on rq.uid=ru.uid
where rq.qid not in(select qid from answers) group by rq.qid order by rq.qid desc
如果您有用户表
,这可能很有用