如何包含在某一天毫无意义的值（APEX）

Question

我有这个查询：

SELECT  
COUNT(ID) AS FREQ,
TO_CHAR(TRUNC(CREATED_AT),'DD-MON') DATES
FROM TICKETS
WHERE TRUNC(CREATED_AT) > TRUNC(SYSDATE) - 32
GROUP BY TRUNC(CREATED_AT)
ORDER BY TRUNC(CREATED_AT) ASC

这会计算上个月每天创建的工单数量。
结果看起来像这样：
（前 10 行）

FREQ    DATES
3   28-DEC
4   04-JAN
8   05-JAN
1   06-JAN
4   07-JAN
5   08-JAN
2   11-JAN
6   12-JAN
3   13-JAN
8   14-JAN

我创建的折线图如下所示：

问题是在没有创建工单的日子（特别是周末），该行直接转到创建工单的那一天。

APEX 或我的查询中是否有办法包含未计算在内的天数？

Answer 1

如评论所述，使用一种行生成器技术，您将创建一个“日历”table 并将其与包含您正在显示的数据的 table 进行外部连接。

像这样（见代码中的评论）：

SQL> with yours (amount, datum) as
  2    -- your sample table
  3    (select 100, date '2021-01-01' from dual union all
  4     select 200, date '2021-01-03' from dual union all
  5     select 300, date '2021-01-07' from dual
  6    ),
  7  minimax as
  8    -- MIN and MAX date (so that they could be used in row generator --> CALENDAR CTE (below)
  9    (select min(datum) min_datum,
 10            max(datum) max_datum
 11     from yours
 12    ),
 13  calendar as
 14    -- calendar, from MIN to MAX date in YOUR table
 15    (select min_datum + level - 1 datum
 16     from minimax
 17     connect by level <= max_datum - min_datum + 1
 18    )
 19  -- final query uses outer join
 20  select c.datum,
 21         nvl(y.amount, 0) amount
 22  from calendar c left join yours y on y.datum = c.datum
 23  order by c.datum;

DATUM          AMOUNT
---------- ----------
01.01.2021        100
02.01.2021          0
03.01.2021        200
04.01.2021          0
05.01.2021          0
06.01.2021          0
07.01.2021        300

7 rows selected.

SQL>

应用于您当前的查询：

WITH
   minimax
   AS
      -- MIN and MAX date (so that they could be used in row generator --> CALENDAR CTE (below)
      (SELECT MIN (created_at) min_datum, MAX (created_at) max_datum
         FROM tickets),
   calendar
   AS
      -- calendar, from MIN to MAX date in YOUR table
      (    SELECT min_datum + LEVEL - 1 datum
             FROM minimax
       CONNECT BY LEVEL <= max_datum - min_datum + 1)
  -- final query uses outer join
  SELECT COUNT (t.id) AS freq, TO_CHAR (TRUNC (c.datum), 'DD-MON') dates
    FROM calendar c LEFT JOIN tickets t ON t.created_at = c.datum
   WHERE TRUNC (t.created_at) > TRUNC (SYSDATE) - 32
GROUP BY TRUNC (c.datum)
ORDER BY dates ASC

Answer 2

@Littlefoot 的回答很完美。但这里有一种厚颜无耻的方式来获得类似 table 的格式匹配 OP 输出。为此使用一个简单的 cte。

   WITH cte AS (
     SELECT To_Char(Trunc(SYSDATE - ROWNUM),'DD-MON') dtcol
       FROM DUAL 
    CONNECT BY ROWNUM < 366
    )
    SELECT * FROM cte

这里是db<>fiddle

然后你就可以简单地加入这个cte来填补空缺日期。因为原始输出列 date 看起来像一个字符串列。
connect by 仅适用于 oracle。但我认为您仍然可以使用递归 cte 在其他支持递归 cte 的 DBMS 中获得类似的结果。

Answer 3

我添加了一个 with 子句来生成过去 31 天，然后我离开加入了你的基地 table，如下所示。

with last_31_days as (
select trunc(sysdate) - 32 + level dt from dual connect by trunc(sysdate) - 32 + level < trunc(sysdate)
)
SELECT  
nvl(COUNT(t.ID), 0) AS FREQ,
TO_CHAR(
        nvl(TRUNC(t.CREATED_AT), a.dt)
    ,'DD-MON') DATES
FROM last_31_days a 
    LEFT JOIN TICKETS t 
        ON TRUNC(t.CREATED_AT) = a.dt 
GROUP BY nvl(TRUNC(t.CREATED_AT), a.dt)
ORDER BY 2 ASC
;

如何包含在某一天毫无意义的值（APEX）

How to include values that count nothing on certain day (APEX)

sql

oracle

plsql

oracle-apex

oracle-apex-20.2