爲每個左連接行匹配重複所有基錶行

Question

我無法簡潔地描述我需要的內容，所以編輯標題的任何幫助都會被讚賞！

我有3個表：

1. Jobs（具有JobID PK）
2. JobsDetail（具有JobID FK和DepartmentsID FK）
3. Departments（具有DepartmentsID PK）

Departments將有很少的記錄（〜10）

如果我有10個部門行，我需要爲每個Jobs記錄重複所有10行。不在作業的JobsDetail記錄中的DepartmentID將在「作業」列中顯示NULL值。隨着一個Jobs記錄，典型LEFT JOIN工作我希望它的方式：

Select d.Department, jobs.JobIdentifier 
From Departments d 
LEFT JOIN (Select Distinct j.JobID, j.JobIdentifier, DepartmentID, 
      From Jobs j 
      Join JobsDetail jd on j.JobID = jd.JobID) jobs on d.DepartmentID = jobs.DepartmentID 

產生這些結果：

Department JobIdentifier 
310   NULL 
320   NULL 
430   NULL 
450   NULL 
460   NULL 
500   NULL 
530   1000 
533   1000 
534   1000 
535   NULL 

當然，當添加了另一個作業記錄時，我看到：

Department JobIdentifier 
310   2000 
320   NULL 
430   NULL 
450   NULL 
460   2000 
500   NULL 
530   1000 
533   1000 
534   1000 
534   2000 
535   NULL 

我需要的是這樣的：

Department JobIdentifier 
310   NULL 
320   NULL 
430   NULL 
450   NULL 
460   NULL 
500   NULL 
530   1000 
533   1000 
534   1000 
535   NULL 
310   2000 
320   NULL 
430   NULL 
450   NULL 
460   2000 
500   NULL 
530   NULL 
533   NULL 
534   2000 
535   NULL 

這是如何實現的？

這裏是從表中的一些測試數據：

JobID    SubPlantID JobIdentifier          PartFamilyID OrderDate    OrderedBy           OrderQuantity DueDate     SpecialInstructions                                                            PrintDate    PrintedBy           StartDate    StartedBy           ProducedQuantity ReprintNumber CompletedDate   Location 
-------------------- ----------- -------------------------------------------------- ------------ ----------------------- -------------------------------------------------- ------------- ----------------------- ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- ----------------------- -------------------------------------------------- ----------------------- -------------------------------------------------- ---------------- ------------- ----------------------- -------------------------------------------------- 
2     1   1000            1   2012-12-21 13:20:00.000 Keith            1    2012-12-28 00:00:00.000                                                                 NULL     NULL            2012-12-28 00:00:00.000 NULL            NULL    0    NULL     NULL 
3     1   2000            1   2013-01-03 00:00:00.000 Jon            10   2013-01-10 00:00:00.000 NULL                                                                NULL     NULL            NULL     NULL            NULL    0    NULL     NULL 

JobsDetailID   JobID    Operation FirstStartDate   OperationQuantity OperationStatusTypeID OperationDescription                                                           DepartmentID WorkCenterID UserName 
-------------------- -------------------- --------- ----------------------- ----------------- --------------------- -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- ------------ ------------ -------------------------------------------------- 
1     2     10  NULL     1     2      Weld                                                               1   2   keith 
2     2     20  NULL     1     3      Punch                                                               1   1   keith 
3     2     30  NULL     1     2      Form                                                               3   5   jon 
4     2     40  NULL     1     3      Paint                                                               2   4   jon 
6     2     50  NULL     1     3      Glue                                                               2   4   jwood 
9     2     60  NULL     1     2      Eat                                                               3   5   jon 
10     3     20  NULL     10    1      Punch                                                               10   18   Jon Wrye 
11     3     30  NULL     10    0      Form                                                               15   29   Jon Wrye 
12     3     40  NULL     10    0      Weld                                                               13   24   Jon Wrye 
13     3     10  NULL     10    2      Start                                                               1   1   jwrye 
14     3     50  NULL     10    0      Finish                                                               1   2   jwrye 

DepartmentID Department 
------------ -------------------------------------------------- 
1   534 
2   533 
3   530 
4   535 
5   500 
6   450 
7   430 
8   200 
9   240 
10   232 
11   220 
12   300 
13   460 
14   320 
15   310 

Answer 1

你應該用交叉作業和部門之間的連接開始，然後構建從那裏查詢：

Select d.Department, jobs.JobIdentifier 
From Departments d cross join 
     (select distinct JobIdentifier from Jobs j) ji LEFT JOIN 
     (Select Distinct j.JobID, j.JobIdentifier, DepartmentID, 
     From Jobs j Join 
       JobsDetail jd 
       on j.JobID = jd.JobID 
     ) jobs 
     on d.DepartmentID = jobs.DepartmentID and 
      ji.jobidentifer = jobs.jobIDentifier 

我有點上的JobId和JobIdentifier之間的區別不清楚，所以這可能不完全正確。

如果添加ji.JobIdentifier到select列表中，你會看到它的工作部門應該屬於，即使沒有匹配。

Answer 2

這如何辦？

select d.Department, CASE WHEN d.DepartmentId = jj.DepartmentID THEN jj.JobID ELSE NULL END

from Department d, (SELECT j.JobID, jd.DepartmentID FROM Jobs j left outer join JobDetail jd on j.JobID = jd.JobID) as jj

Answer 3

您需要劃掉目錄（有交叉連接），部門和職位，然後做一個左連接到你的關係表

http://sqlfiddle.com/#!6/277ec/30

Answer 4

我不知道我是否明白你想要做什麼，所以讓我們從頭開始。以下聲明以何種方式證明不足？

Select 
    d.Department, 
    j.JobIdentifier 
From 
    Departments d 
    Left Join JobDetails jd On d.Id = jd.DepartmentId 
    Left Join Jobs j On jd.JobId = j.Id