查询出多条记录，取最大或最小的某条件的记录，取唯一记录

案例1：
SELECT * FROM(
SELECT t.*, max(t.visit_date) over(partition by t.cust_id) visit_date1 FROM(
select a.cust_id, a.assess_result, max(a.visit_date) visit_date
from yx_cust_guide a
inner join yx_cust_guide b on a.cust_id = b.cust_id
where a.visit_date < b.visit_date and a.status in('03','04','09')
AND a.CUST_ID='1450260000207'

group by a.cust_id, a.assess_result
) t
) t1 WHERE t1.visit_date = t1.visit_date1

ORDER BY a.CUST_ID

案例2：

WITH tbl(ID, CRT_DATE, CRT_DPT, CRT_EMP, RECV_DPT, RECV_EMP, INFO_TYPE, DETAIL_TYPE, SUMMARY, STATUS, OPT) AS
(
--select id, crt_date, crt_dpt, crt_emp, recv_dpt, recv_emp,
--info_type, detail_type, summary, status, opt
--from (
select i.id, replace(substr(i.crt_time,1,10),'-','') crt_date,
o1.organ_name crt_dpt, o2.organ_name crt_emp,
o3.organ_name recv_dpt, o4.organ_name recv_emp,
i.info_type, d.detail_name detail_type, i.summary, i.status,
'01' opt
from yx_info_interact i
left join pub_organ o1 on i.crt_dpt_id = o1.id
left join pub_organ o2 on i.crt_emp_id = o2.id
left join pub_organ o3 on i.rece_dpt_id = o3.id
left join pub_organ o4 on i.rece_emp_id = o4.id
left join yx_info_type_detail d on i.type_detail = d.id
where 1=1
union
select i.id, replace(substr(i.crt_time,1,10),'-','') crt_date,
o1.organ_name crt_dpt, o2.organ_name crt_emp,
o3.organ_name recv_dpt, o4.organ_name recv_emp,
i.info_type, d.detail_name detail_type, i.summary, i.status,
'02' opt
from yx_info_interact i
left join pub_organ o1 on i.crt_dpt_id = o1.id
left join pub_organ o2 on i.crt_emp_id = o2.id
left join pub_organ o3 on i.rece_dpt_id = o3.id
left join pub_organ o4 on i.rece_emp_id = o4.id
left join yx_info_type_detail d on i.type_detail = d.id
where 1=1
union
select i.id, replace(substr(i.crt_time,1,10),'-','') crt_date,
o1.organ_name crt_dpt, o2.organ_name crt_emp,
o3.organ_name recv_dpt, o4.organ_name recv_emp,
i.info_type, d.detail_name detail_type, i.summary, i.status,
'03' opt
from yx_info_interact i
left join pub_organ o1 on i.crt_dpt_id = o1.id
left join pub_organ o2 on i.crt_emp_id = o2.id
left join pub_organ o3 on i.rece_dpt_id = o3.id
left join pub_organ o4 on i.rece_emp_id = o4.id
left join yx_info_type_detail d on i.type_detail = d.id
where 1=1
--)t
)
--SELECT ROW_NUMBER () OVER (PARTITION BY t.id ORDER BY t.id), t.* FROM tbl t order BY id DESC;

--SELECT ROW_NUMBER () OVER (order BY t.id) rec_id, t.* FROM tbl t order BY id DESC;

SELECT * FROM(
select t.*,max(t.status) over(partition by t.id) status1 from tbl t
)t1 WHERE t1.status = t1.status1

--select cno,sno,score from (
--select t.cno,t.sno,t.score,max(t.score) over(partition by t.cno) score1 from sc t
--)t1 where t1.score=t1.score1