我应该如何在 PL/SQL 过程中临时存储数据？

Question

我对 PL/SQL 很陌生。我在一个名为“FLEX_PANEL_INSPECTIONS”的初始表中有数据，我试图使用 PL/SQL 过程在名为“PANEL_STATUS_2”的第二个表中进行汇总。然而，由于数据的性质，我不得不写一个case语句来正确地总结来自FLEX_PANEL_INSPECTIONS的数据。因此，我创建了第三个中间表来连接两者（名为“PANEL_STATUS_1”），因为 case 语句不允许 group by 子句中专门对数据进行排序的列（据我所知 - 当我尝试这样做）。我不想将数据存储在中间表中 - 有什么方法可以使其成为临时表（即仅在过程运行时存在，以便不保留来自“PANEL_STATUS_1”的数据）；在过程中创建视图，还是完全不需要中间表？

对我对 PL/SQL 的错误/误解的任何帮助或批评将不胜感激。这是我写的代码：

create or replace procedure PANEL_STATUS_PROCEDURE (panel_lot_id in number) as

begin

--Populate intermediate table with information about the status of the panels.
insert into PANEL_STATUS_1 (FLEX_LOT_ID, FLEX_PANEL_DMX, FLEX_PANEL_STATUS)   
select FLEX_LOT_ID, FLEX_PANEL_DMX,

--Sum the status values of the 4 panel inspections. A panel passes if and only if this sum = 4. 
case sum (FLEX_PANEL_STATUS)
    when 4 then 1
    else 0

end as new_panel_status

from FLEX_PANEL_INSPECTIONS
where FLEX_LOT_ID = panel_lot_id
group by FLEX_LOT_ID, FLEX_PANEL_DMX;

--Add information about the machine ID and the upload time to this table.
insert into PANEL_STATUS_2 (FLEX_LOT_ID, FLEX_PANEL_DMX, FLEX_PANEL_STATUS, MACHINE_ID, UPLOAD_TIME)
select distinct PANEL_STATUS_1.*, MACHINE_ID, UPLOAD_TIME
from PANEL_STATUS_1, FLEX_PANEL_INSPECTIONS

where (FLEX_PANEL_INSPECTIONS.FLEX_LOT_ID = PANEL_STATUS_1.FLEX_LOT_ID
       and FLEX_PANEL_INSPECTIONS.FLEX_PANEL_DMX = PANEL_STATUS_1.FLEX_PANEL_DMX)

and FLEX_PANEL_INSPECTIONS.FLEX_LOT_ID = panel_lot_id;

end PANEL_STATUS_PROCEDURE;
/

Answer 1

您可以将临时表创建为

create global temporary table gtt_panel_status
( column datatype ... )
on commit [delete|preserve] rows;

（在on commit 子句中指定delete 或preserve）。

但是，您通常不需要临时表。您可以尝试使用with 子句（CTE），或者沿select x, y, z from (select your subquery here) 行的内联视图。

编辑：实际上查看您的查询更多，我认为您真正需要的是分析sum，即没有汇总的总数。例如，像这样：

create or replace procedure panel_status_procedure
    ( panel_lot_id in number )
as
begin
    -- Add information about the machine ID and the upload time to this table.
    insert into panel_status_2
         ( flex_lot_id
         , flex_panel_dmx
         , flex_panel_status
         , machine_id
         , upload_time )
    select distinct
           flex_lot_id
         , flex_panel_dmx
         , case sum(flex_panel_status) over (partition by flex_lot_id, flex_panel_dmx)
               when 4 then 1
               else 0
           end
         , machine_id
         , upload_time
    from   flex_panel_inspections pi
    where  pi.flex_lot_id = panel_lot_id;

end panel_status_procedure;