如何在发生的特定状态之后返回下一个状态答案

【问题标题】：How to return next status following a specific status that has occured如何在发生的特定状态之后返回下一个状态
【发布时间】：2021-11-09 02:23:14
【问题描述】：

我希望在收到订单后返回下一个状态，但只希望捕获以下列表中的某些状态：“已发货”、“部分发货”、“已取消” 下面是订单表

Order ID	Order Status	Date
1	Received	1/1/2021
1	Partially Shipped	1/1/2021
1	Returned	1/2/2021
1	Received	1/2/2021
1	Shipped	1/3/2021
2	Received	1/1/2021
2	Acknowledged	1/1/2021
2	Shipped	1/1/2021

如您所见，订单 ID 2 收到后的以下状态为已确认，但我只想获取以下列表中的下一个状态：“已发货”、“部分发货”、“已取消” 因此，以下输出将是正确的，跳过确认并返回已发货

Order ID	Order Status	Date
1	Partially Shipped	1/1/2021
1	Shipped	1/3/2021
2	Shipped	1/1/2021

【问题讨论】：

请不要张贴桌子的照片。只需将其显示为文本。您将需要查看 oracle 窗口/分析函数。
你能告诉我们你的尝试吗？

标签： sql oracle

【解决方案1】：

您可以使用带有IGNORE NULLS 子句的条件LAG 分析语句：

SELECT Order_id,
       Order_status,
       "DATE"
FROM   (
  SELECT t.*,
         LAG(
           CASE
           WHEN order_status IN ('Received', 'Shipped', 'Partially Shipped', 'Cancelled')
           THEN order_status
           END
         ) IGNORE NULLS OVER (PARTITION BY order_id ORDER BY "DATE") AS prev_status
  FROM   table_name t
)
WHERE  prev_status = 'Received'
AND    order_status IN ('Shipped', 'Partially Shipped', 'Cancelled')

其中，对于样本数据：

CREATE TABLE table_name (Order_ID, Order_Status, "DATE") AS
SELECT 1, 'Received',          DATE '2021-01-01' FROM DUAL UNION ALL
SELECT 1, 'Partially Shipped', DATE '2021-01-01' FROM DUAL UNION ALL
SELECT 1, 'Shipped',           DATE '2021-01-02' FROM DUAL UNION ALL
SELECT 1, 'Returned',          DATE '2021-02-01' FROM DUAL UNION ALL
SELECT 1, 'Received',          DATE '2021-02-01' FROM DUAL UNION ALL
SELECT 1, 'Shipped',           DATE '2021-03-01' FROM DUAL UNION ALL
SELECT 2, 'Received',          DATE '2021-01-01' FROM DUAL UNION ALL
SELECT 2, 'Acknowledged',      DATE '2021-01-01' FROM DUAL UNION ALL
SELECT 2, 'Shipped',           DATE '2021-01-01' FROM DUAL UNION ALL
SELECT 3, 'Received',          DATE '2021-01-01' FROM DUAL UNION ALL
SELECT 3, 'Acknowledged',      DATE '2021-02-01' FROM DUAL UNION ALL
SELECT 4, 'Received',          DATE '2021-01-01' FROM DUAL UNION ALL
SELECT 4, 'Acknowledged',      DATE '2021-02-01' FROM DUAL UNION ALL
SELECT 4, 'Received',          DATE '2021-01-01' FROM DUAL;

输出：

ORDER_ID ORDER_STATUS DATE

1 Partially Shipped 2021-01-01 00:00:00

1 Shipped 2021-03-01 00:00:00

2 Shipped 2021-01-01 00:00:00

ORDER_ID	ORDER_STATUS	DATE
1	Partially Shipped	2021-01-01 00:00:00
1	Shipped	2021-03-01 00:00:00
2	Shipped	2021-01-01 00:00:00

db小提琴here

【讨论】：

【解决方案2】：

您可以使用match_recognize 来处理这里看起来合适的情况，因为它可以处理要包含的状态的重复。它适用于所有受支持的版本（自 12c 起）。

我添加了额外的行来显示它是如何处理的，例如'Partially Shipped' 之后的'Shipped'，以及所需状态列表中缺少下一个状态（如order_id = 3）。

with a (Order_ID, Order_Status, dt) as (
  select 1, 'Received', date '2021-01-01'           from dual union all
  select 1, 'Partially Shipped', date '2021-01-01'  from dual union all
  select 1, 'Shipped', date '2021-01-02'           from dual union all
  select 1, 'Returned', date '2021-02-01'           from dual union all
  select 1, 'Received', date '2021-02-01'           from dual union all
  select 1, 'Shipped', date '2021-03-01'           from dual union all
  select 2, 'Received', date '2021-01-01'           from dual union all
  select 2, 'Acknowledged', date '2021-01-01'       from dual union all
  select 2, 'Shipped', date '2021-01-01'           from dual union all
  select 3, 'Received', date '2021-01-01'           from dual union all
  select 3, 'Acknowledged', date '2021-02-01'       from dual union all
  select 3, 'Received', date '2021-03-01'           from dual union all
  select 4, 'Received', date '2021-01-01'           from dual union all
  select 4, 'Acknowledged', date '2021-02-01'       from dual union all
  select 4, 'Received', date '2021-03-01'           from dual union all
  select 4, 'Acknowledged', date '2021-03-02'       from dual union all
  select 4, 'Shipped', date '2021-03-05'       from dual
)
select *
from a
match_recognize (
  partition by order_id
  order by dt asc
  all rows per match
  /*Return the next status after 'Received', that is in a list of interest*/
  pattern (
    {- received -} /*Exclude 'Received' from output*/
    {- exclude* -} /*Exclude "other" statuses after 'Received'*/
    next? /*And include the next status that should be in the list.
            Marked as optional to allow previous exclusion group
            to catch not listed statuses*/
  )
  define
    received as order_status = 'Received',
    /*Other statuses (that are out of interest)*/
    exclude as order_status not in ('Shipped', 'Partially Shipped', 'Cancelled'),
    /*To break match if the next status is not from the list*/
    next as order_status in ('Shipped', 'Partially Shipped', 'Cancelled')
)

ORDER_ID | DT |订单状态 --------: | :--------- | :----------- 1 | 2021-01-02 |已发货 1 | 2021-03-01 |已发货 2 | 2021-01-01 |已发货 4 | 2021-03-05 |已发货

db小提琴here

【讨论】：

是否需要定义next AS order_status not in ('Shipped', 'Partially Shipped', 'Cancelled')，否则会发现“下一个”状态返回为“已接收”？
我不应该在我之前的评论中包含“不”；那是我的复制粘贴错误。很抱歉有任何混淆。
@MT0 谢谢！我也在排除列表之后添加了这个带有Received 的测试用例。我认为next 应该只是一个所需状态的列表，因为我们需要它们而不是'Received'（它更冗长）。还重新组织了exclude 模式，因为如果'Received' 将被捕获，那么到目前为止还没有满足列表中的任何状态，所以匹配应该跨越更多行，直到它达到next 模式。我已经删除了我之前的误导性评论。