從計劃表中查找工作順序？

Question

我試圖根據存儲在Oracle數據庫中的表寫出一個批處理作業計劃。

我真的不知道從哪裏開始。

表只有兩個相關列：

JOBSTREAM  | FOLLOW_JOBSTREAM 

作業流是要運行作業流的名稱。 FOLLOW_JOBSTREAM是在作業流運行之前必須完成的作業流的名稱。在某些情況下，一個JOBSTREAM條目有幾個FOLLOW_JOBSTREAM條目。

例如：

JS001  JS028 
JS001A  JS039 
JS001B  JS001A 
JS002  JS001A 
JS002  JS001B 

有沒有一種方法排序這些使用PL/SQL？

謝謝！

Answer 1

首先，我們需要從兩個列有層次的聯繫完全作業列表：

select 
    all_jobs.job_id    as jobstream, 
    job_depends.follow_jobstream as parent_jobstream 
    from 
    (
     select jobstream job_id from job_list 
     union 
     select follow_jobstream job_id from job_list 
    ) all_jobs, 
    job_list job_depends 
    where 
    job_depends.jobstream (+) = all_jobs.job_id 

然後確定每個崗位的深度。

with full_job_list as (
    select 
    all_jobs.job_id    as jobstream, 
    job_depends.follow_jobstream as parent_jobstream 
    from 
    (
     select jobstream job_id from job_list 
     union 
     select follow_jobstream job_id from job_list 
    ) all_jobs, 
    job_list job_depends 
    where 
    job_depends.jobstream (+) = all_jobs.job_id 
) 
select 
    CONNECT_BY_ROOT jobstream   as jobstream, 
    level        as lvl, 
    CONNECT_BY_ROOT parent_jobstream  as preceding_jobstream, 
    sys_connect_by_path(jobstream, '<-') as path_illustration 
from 
    full_job_list 
connect by 
    prior parent_jobstream = jobstream 

最後根據深度安排工作。同一深度的作業可以按任意順序工作。

with full_job_list as (
    select 
    all_jobs.job_id    as jobstream, 
    job_depends.follow_jobstream as parent_jobstream 
    from 
    (
     select jobstream job_id from job_list 
     union 
     select follow_jobstream job_id from job_list 
    ) all_jobs, 
    job_list job_depends 
    where 
    job_depends.jobstream (+) = all_jobs.job_id 
) 
select 
    jobstream, 
    depth, 
    preceding_jobstream 
from (
    select distinct 
    jobstream, 
    ( 
     last_value(lvl ignore nulls) 
     over (partition by jobstream 
      order by lvl 
      rows between unbounded preceding and unbounded following 
      ) 
    ) as depth, 
    (
     last_value(preceding_jobstream ignore nulls) 
     over (partition by jobstream 
      order by lvl 
      rows between unbounded preceding and unbounded following 
      ) 
    ) as preceding_jobstream 
    from (
    select 
     CONNECT_BY_ROOT jobstream  as jobstream, 
     level       as lvl, 
     CONNECT_BY_ROOT parent_jobstream as preceding_jobstream 
    from 
     full_job_list 
    connect by 
     prior parent_jobstream = jobstream 
) 
) 
order by depth, jobstream 

SQL Fiddle

更新糾正，以獲得完整的任務列表和添加前的工作。

Update2更正了路徑方向的錯誤。

Answer 2

Hierarchical queries可以幫助你在這種情況下：

SELECT JOBSTREAM, FOLLOW_JOBSTREAM 
FROM <jobstreams> 
START WITH FOLLOW_JOBSTREAM NOT IN (SELECT JOBSTREAM 
            FROM jobstreams 
            ) 
CONNECT BY PRIOR JOBSTREAM = FOLLOW_JOBSTREAM 

SQL Fiddle

Answer 3

有在調度多個作業鏈接在一起的Oracle官方方法。

DBMS_Scheduler允許您根據鏈中先前步驟的退出條件定義具有依賴關係的作業鏈。它可能比本土方法更加靈活和複雜，所以我將在未來考慮遷移到它。