混合在一起通过Oracle内部连接和求和 [英] Mixing together Connect by, inner join and sum with Oracle

问题描述

我需要有关oracle查询的帮助.

I need help with a oracle query.

这是我的设置:

我有2个表，分别称为任务"和时间表". 任务"表是一个递归表，这样每个任务可以具有多个子任务.每个时间表都与一个任务(不一定是根"任务)相关联，并包含处理该任务的小时数.

I have 2 tables called respectively "tasks" and "timesheets". The "tasks" table is a recursive one, that way each task can have multiple subtasks. Each timesheet is associated with a task (not necessarily the "root" task) and contains the number of hours worked on it.

示例:

id:1 |名称:任务A | parent_id:NULL

id:1 | name: Task A | parent_id: NULL

id:2 |名称:任务A1 | parent_id:1

id:2 | name: Task A1 | parent_id: 1

id:3 |名称:任务A1.1 | parent_id:2

id:3 | name: Task A1.1 | parent_id: 2

id:4 |名称:任务B | parent_id:NULL

id:4 | name: Task B | parent_id: NULL

id:5 |名称:任务B1 | parent_id:4

id:5 | name: Task B1 | parent_id: 4

id:1 | task_id:1 |小时:1

id:1 | task_id: 1 | hours: 1

id:2 | task_id:2 |小时:3

id:2 | task_id: 2 | hours: 3

id:3 | task_id:3 |小时:1

id:3 | task_id:3 | hours: 1

id:5 | task_id:5 |小时:1 ...

id:5 | task_id:5 | hours:1 ...

我想要一个查询，该查询将返回任务层次结构"上所有工作时间的总和.如果我们看一下前面的示例，这意味着我希望获得以下结果:

I want a query that will return the sum of all the hours worked on a "task hierarchy". If we take a look at the previous example, It means I would like to have the following results:

任务A-5小时|任务B-1小时(s)

task A - 5 hour(s) | task B - 1 hour(s)

SELECT TaskName, Sum(Hours) "TotalHours" 
FROM (
    SELECT replace(sys_connect_by_path(decode(level, 1, t.name), '~'), '~') As TaskName, 
    ts.hours as hours
    FROM tasks t INNER JOIN timesheets ts ON t.id=ts.task_id
    START WITH PARENTOID=-1
    CONNECT BY PRIOR t.id = t.parent_id
    )
GROUP BY TaskName Having Sum(Hours) > 0 ORDER BY TaskName

几乎可以正常工作.唯一的问题是，如果没有针对根任务的时间表，它将跳过整个层次结构...但是可能会有针对子行的时间表，而这正是任务B1发生的事情.我知道是导致问题的原因是内部联接"部分，但是我不确定如何摆脱它.

And it almost work. THe only problem is that if there are no timesheet for a root task, it will skip the whole hieararchy... but there might be timesheets for the child rows and it is exactly what happens with Task B1. I know it is the "inner join" part that is causing my problem but I'm not sure how can I get rid of it.

有什么办法解决这个问题吗?

Any idea how to solve this problem?

谢谢

推荐答案

这样的作品有用吗?我遇到过与您类似的情况，我只是从分层查询中删除了联接，然后才应用它，以免丢失行.

Would something like this work? I've had cases similar to yours, and I simply removed the join from the hierarchical query and applied it only afterward to avoid losing rows.

SELECT TaskName, Sum(ts.hours) "TotalHours" 
FROM (
    SELECT replace(sys_connect_by_path(decode(level, 1, t.name), '~'), '~') As TaskName, t.id
    FROM tasks t
    START WITH PARENTOID=-1
    CONNECT BY PRIOR t.id = t.parent_id
    ) tasks
INNER JOIN timesheets ts ON tasks.id=ts.task_id
GROUP BY TaskName Having Sum(ts.hours) > 0 ORDER BY TaskName

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