Oracle查询：如何从此查询中取消多个结果？

Question

我有以下表格：

CLIENT 
- ID 
- NAME 
- USER 

ORDER 
- ID 
- DATE 
- CLIENT_ID 
- USER 

ORDER_LINE 
- ORDER_ID 
- LINE_ID 
- USER 

用户现场跟踪谁最后修改记录的人。此外，每个订单项可能会被不同的用户修改。

我试图找出来，给一个用户，有什么吩咐他们已经参与了。

select 
client.id, 
client.name, 
order.id, 
order.date, 
case 
    when order_line.user = :user then 'Line Item' 
    when order.user = :user then 'Order' 
    when client.user = :user then 'Client' 
end 
from 
order_line 
join order on order_id = order.id 
join client on order.client_id = client.id 
where 
order_line.user = :user 
or order.user = :user 
or client.user = :user 

问题是，用户可能同时触摸order和order_line表，所以我得到多个结果。添加select distinct不会有帮助，因为case语句的结果在每种情况下都不相同。

有没有办法来重组查询，所以我只有每个订单得到一个结果？

case语句的结果是不是真的那么重要 - 这将是很好，如果我能在别人摸两个表，但只是“行项目”的情况下，得到“行项目，令”将确定。

Answer 1

我提出这个

这将显示该用户改变所有的订单，如果他改变线项目，但不是行项目

SELECT client.id, 
     client.name, 
     order.id, 
     order.date 
    FROM  order 
     JOIN 
      client 
     ON client_id = client.id 
WHERE  order.USER = :USER 
     OR client.USER = :USER 
     OR :USER IN (SELECT USER 
         FROM ORDER_LINE OL 
         WHERE ORDER_LINE.ORDER_ID = ORDER.ID) 

Answer 2

Oracle是否已经GROUP_CONCAT（或相似）MySQL有？

select client_id, name, order_id, date, group_concat(what separator ', ') as changes 
from (
select 
client.id as client_id, 
client.name, 
order.id as order_id, 
order.date, 
case 
    when order_line.user = :user then 'Line Item' 
    when order.user = :user then 'Order' 
    when client.user = :user then 'Client' 
end as what 
from 
order_line 
join order on order_id = order.id 
join client on order.client_id = client.id 
where 
order_line.user = :user 
or order.user = :user 
or client.user = :user 
) as part1 
group by client_id, name, order_id, date; 

Answer 3

如何串联的最后一列，并使用不同的，这样的事情：

select distinct 
client.id, 
client.name, 
order.id, 
order.date, 
case when order_line.user = :user then 'Line Item ' else '' end || 
    case when order.user = :user then 'Order ' else '' end || 
    case when client.user = :user then 'Client ' else '' end 
from 
order_line 
join order on order_id = order.id 
join client on order.client_id = client.id 
where 
order_line.user = :user 
or order.user = :user 
or client.user = :user 

？

Answer 4

尝试类似如下：

select client_id, 
     max(client_name), 
     order_id, 
     max(order_date), 
     max(Line_User), 
     max(Order_User), 
     max(Client_User) 
(select client.id client_id, 
     client.name client_name, 
     order.id order_id, 
     order.date order_date, 
     case when order_line.user = :user then 'Y' else 'N' end Line_User, 
     case when order.user = :user then 'Y' else 'N' end Order_User, 
     case when client.user = :user then 'Y' else 'N' end Client_User 
from order_line 
join order on order_id = order.id 
join client on order.client_id = client.id 
where order_line.user = :user or order.user = :user or client.user = :user) 
group by client_id, order_id;