注：回访表 eb_recall_history 与 eb_recall_result 关联 。eb_recall_history数据量很大，下面的这句SQL能达到要求，但查询速度很慢，寻求优化方案。
select
(select rr_qi_id from eb_recall_result where rr_qq_id = 173 and rr_is_select =1 and rr_rec_id=rec_id and rr_qi_id =184) 呼入限制,
(select rr_qi_id from eb_recall_result where rr_qq_id = 173 and rr_is_select =1 and rr_rec_id=rec_id and rr_qi_id =185) 不知情,
(select rr_qi_id from eb_recall_result where rr_qq_id = 173 and rr_is_select =1 and rr_rec_id=rec_id and rr_qi_id =170) 电话关机,
(select rr_qi_id from eb_recall_result where rr_qq_id = 173 and rr_is_select =1 and rr_rec_id=rec_id and rr_qi_id =171) 用户拒访,
(select rr_qi_id from eb_recall_result where rr_qq_id = 173 and rr_is_select =1 and rr_rec_id=rec_id and rr_qi_id =172) 欠费停机,
(select rr_qi_id from eb_recall_result where rr_qq_id = 173 and rr_is_select =1 and rr_rec_id=rec_id and rr_qi_id =173) 传真电话,
(select rr_qi_id from eb_recall_result where rr_qq_id = 173 and rr_is_select =1 and rr_rec_id=rec_id and rr_qi_id =174) 无人接听,
(select rr_qi_id from eb_recall_result where rr_qq_id = 173 and rr_is_select =1 and rr_rec_id=rec_id and rr_qi_id =175) 无法接通
from eb_recall_history
------解决方案--------------------
select decode(b.rr_qi_id,184, '呼入限制 ',185, '不知情 ',170, '电话关机 ',171, '用户拒访 ',172, '欠费停机 ',
173, '传真电话 ',174, '无人接听 ',175, '无法接通 ', ' ')
from eb_recall_history a,eb_recall_result b
where b.rr_qq_id = 173 and b.rr_is_select =1 and b.rr_rec_id=a.rec_id
------解决方案--------------------
select
max(decode(t2.rr_qi_id,184,rr_qi_id)) 呼入限制,
max(decode(t2.rr_qi_id,185,rr_qi_id)) 不知情,
max(decode(t2.rr_qi_id,170,rr_qi_id)) 电话关机,
max(decode(t2.rr_qi_id,171,rr_qi_id)) 用户拒访,
max(decode(t2.rr_qi_id,172,rr_qi_id)) 欠费停机,
max(decode(t2.rr_qi_id,173,rr_qi_id)) 传真电话,
max(decode(t2.rr_qi_id,174,rr_qi_id)) 无人接听,
max(decode(t2.rr_qi_id,175,rr_qi_id)) 无法接通
from
eb_recall_history t1,eb_recall_result t2
where t2.rr_rec_id=t1.rec_id and
t2.rr_is_select=1 and
t2.rr_qq_id=173
group by t1.rec_id