使用 With 子句的相关 SQL 查询

Question

我正在尝试修改以下查询：

SELECT START_END.*, START_END.LOAD_TIME_END - START_END.LOAD_TIME_START
FROM
(
  SELECT START.JOB_ID, START.LOAD_TIME_START, END.LOAD_TIME_END
  FROM
  (
    SELECT JOB_ID,LOAD_TIME AS LOAD_TIME_START
    FROM JOB_CTRL_RECON JCR
    INNER JOIN
    (
      SELECT JOB_ID AS JOB_ID_S, MAX(RECON_ID) AS S_MAX_RECON_ID
      FROM job_ctrl_recon
      where job_id in ('1','2')
      and count_type = 'Source'
      GROUP BY JOB_ID
    ) SMAX
    ON JCR.JOB_ID = SMAX.S_MAX_RECON_ID
    AND JCR.RECON_ID = SMAX.RECON_ID
  ) START
  INNER JOIN
  (
    SELECT JOB_ID,LOAD_TIME AS LOAD_TIME_END FROM JOB_CTRL_RECON JCR INNER JOIN 
    (
      SELECT JOB_ID AS JOB_ID_T, MAX(RECON_ID) AS T_MAX_RECON_ID
      FROM job_ctrl_recon
      where job_id in ('1','2')
      and count_type = 'Target'
      GROUP BY JOB_ID
    ) TMAX
    ON JCR.JOB_ID = TMAX.T_MAX_RECON_ID
    AND JCR.RECON_ID = TMAX.RECON_ID
  ) END
  ON START.JOB_ID = END.JOB_ID
) START_END

使用 with 子句的查询如下：

如何使用 with 子句消除 where job_id in ('1','2') 的多次使用，如下所示：

WITH A AS 
(
  SELECT JOB_ID FROM JOB_CTRL_RECON WHERE JOB_ID IN ('60','67')
)
SELECT START_END.*, START_END.LOAD_TIME_END - START_END.LOAD_TIME_START
FROM 
(
  SELECT START.JOB_ID, START.LOAD_TIME_START, END.LOAD_TIME_END
  FROM
  (
    SELECT JOB_ID,LOAD_TIME AS LOAD_TIME_START
    FROM JOB_CTRL_RECON JCR
    INNER JOIN 
    (
      SELECT JOB_ID AS JOB_ID_S, MAX(RECON_ID) AS S_MAX_RECON_ID
      FROM job_ctrl_recon
      where job_id in (????)
      and count_type = 'Source'
      GROUP BY JOB_ID
    ) SMAX
    ON JCR.JOB_ID = SMAX.S_MAX_RECON_ID
    AND JCR.RECON_ID = SMAX.RECON_ID
  ) START
  INNER JOIN 
  (
    SELECT JOB_ID,LOAD_TIME AS LOAD_TIME_END
    FROM JOB_CTRL_RECON JCR
    INNER JOIN 
    (
      SELECT JOB_ID AS JOB_ID_T, MAX(RECON_ID) AS T_MAX_RECON_ID
      FROM job_ctrl_recon
      where job_id in (????)
      and count_type = 'Target'
      GROUP BY JOB_ID
    ) TMAX
    ON JCR.JOB_ID = TMAX.T_MAX_RECON_ID
    AND JCR.RECON_ID = TMAX.RECON_ID
  ) END
  ON START.JOB_ID = END.JOB_ID
) START_END, A
WHERE START_END.JOB_ID = A.JOB_ID

Answer 1

试试这个。希望能帮助到你。谢谢

old:     where job_id in (????)
new:     where job_id in (select JOB_ID from A)

Answer 2

而不是 WITH，您可以使用带有分析函数的 KEEP 来简化代码。代码起初有点奇怪，但它只允许您指定 JOB_ID 一次，并且只需要从 table 中读取一次。

--Load time start and end for each JOB_ID, based on the latest RECON_ID.
select
    job_id,
    max(load_time_start) load_time_start,
    max(load_time_end) load_time_end,
    max(load_time_end) - max(load_time_start) diff
from
(
    --First and last load time for each set of rows, with some debug data.
    select job_id, count_type, recon_id, load_time
        ,last_value(case when count_type = 'Source' then load_time else null end)
            over (
                partition by job_id, count_type
                order by recon_id
                rows between unbounded preceding and unbounded following
            ) load_time_start
        ,last_value(case when count_type = 'Target' then load_time else null end)
            over (
                partition by job_id, count_type
                order by recon_id
                rows between unbounded preceding and unbounded following
            ) load_time_end
    from job_ctrl_recon
    where job_id in (1,2)
)
group by job_id
order by job_id;

为此table和数据：

create table job_ctrl_recon(job_id number, recon_id number, count_type varchar2(100), load_time date);

alter session set nls_date_format = 'DD-Mon-RR';

insert into job_ctrl_recon
select 1, 400, 'Source', '24-Feb-18' from dual union all
select 1, 40,  'Source', '23-Feb-18' from dual union all
select 1, 89,  'Target', '25-Feb-18' from dual union all
select 1, 8,   'Target', '25-Feb-18' from dual union all
select 2, 700, 'Source', '24-Feb-18' from dual union all
select 2, 8,   'Source', '23-Feb-18' from dual union all
select 2, 567, 'Target', '25-Feb-18' from dual union all
select 2, 45,  'Target', '25-Feb-18' from dual union all
select 2, 678, 'Target', '25-Feb-18' from dual;

commit;

这些是结果：

JOB_ID   LOAD_TIME_START   LOAD_TIME_END   DIFF
------   ---------------   -------------   ----
1        2018-02-24        2018-02-25      1
2        2018-02-24        2018-02-25      1

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