试题选项表t_ems_item_option中有item_id试题id,option_id选项id,is_correct是否正确答案
例如 item_id option_id is_correct试题1 a f
试题1 b f
试题1 c f
试题1 d t试题2 a f
试题2 b f
试题2 c f
试题2 d f
求找到试题2
例如 item_id option_id is_correct试题1 a f
试题1 b f
试题1 c f
试题1 d t试题2 a f
试题2 b f
试题2 c f
试题2 d f
求找到试题2
select st from(
select count(1) n1 ,st from T group by st) a
join
(select count(1) n2,st,iscorect from T group by st,iscorect)
b
on a.st=b.st
where a.n1=b.n2
SELECT
item_id
FROM t_ems_item_option
GROUP BY
item_id
HAVING
COUNT(item_id) = COUNT(IF(is_correct = 'f', item_id, NULL))
SELECT
item_id
FROM
t_ems_item_option
GROUP BY
item_id
HAVING
SUM(CASE WHEN is_correct = 't' THEN 1 ELSE 0 END) = 0