关于建立视图的主键问题！求教
现在业务需要建个视图
但建立的视图，每一条数据都没有一个字段可以用来作为唯一标示来区别这条数据。
请问如何解决？
可以增加个序列吗？如果可以，怎么写？
附上视图脚本：
- SQL code
CREATE OR REPLACE VIEW v_Load_Dis_Charge_info( nums, vessel_m, voyage_n, size_q, operator_c, status_c, type_c, inland_trade_i, shipping_status_c ) AS select count(*) as nums, loading_vessel_m, LOADING_VOYAGE_N, size_q, out_slot_operator_c, status_c, type_c, inland_trade_i, '出口' as shipping_status_c from cntr where shipping_status_c in ('EX','RE','RS') group by out_slot_operator_c,size_q,status_c,type_c,inland_trade_i,loading_vessel_m,LOADING_VOYAGE_N union select count(*) as nums, discharge_vessel_m, discharge_VOYAGE_N, size_q, in_slot_operator_c, status_c, type_c, inland_trade_i, '进口' as shipping_status_c from cntr where shipping_status_c in ('IM','OL') group by in_slot_operator_c,size_q,status_c,type_c,inland_trade_i,discharge_vessel_m,discharge_VOYAGE_N[解决办法]
不可以增加序列，因为视图是通过表建成的。他的列都属于表里的列
你可以通过一张表里的序列号来辨别数据
[解决办法]
我的建议是你把group by的所有字段当成联合主键。
[解决办法]
或者
select
nums,
loading_vessel_m,
LOADING_VOYAGE_N,
size_q,
out_slot_operator_c,
status_c,
type_c,
inland_trade_i,
shipping_status_c,
rownum as id
from (
select
count(*) as nums,
loading_vessel_m,
LOADING_VOYAGE_N,
size_q,
out_slot_operator_c,
status_c,
type_c,
inland_trade_i,
'出口' as shipping_status_c
from cntr
where shipping_status_c in ('EX','RE','RS')
group by out_slot_operator_c,size_q,status_c,type_c,inland_trade_i,loading_vessel_m,LOADING_VOYAGE_N
union
select
count(*) as nums,
discharge_vessel_m,
discharge_VOYAGE_N,
size_q,
in_slot_operator_c,
status_c,
type_c,
inland_trade_i,
'进口' as shipping_status_c
from cntr
where shipping_status_c in ('IM','OL')
group by in_slot_operator_c,size_q,status_c,type_c,inland_trade_i,discharge_vessel_m,discharge_VOYAGE_N
)
[解决办法]