如何從兩個不同的表中獲取數據，如何將其鏈接到第三個表中的數據，以及如何在單個報表中獲取所有數據？

Question

我在這里有點麻煩。 我有兩個不同的表，一個表存儲特定橫幅每天和每個用戶在網站上的印象數，另一個表存儲在給定日期向任何用戶發送的電子郵件數。

有點像這樣：

BANNERS

DATE     USER_ID CLIENT_ID BANNER_ID IMPRESSIONS
________ _______ _________ ________ ___________
04/05/11 AX745   CC        CC45      4  
04/05/11 AX745   KC        KC66      1
04/07/11 XY555   DP        DP45      2

和：

EMAILS

DATE     USER_ID EMAIL_ID CLIENT_ID
________ _______ ________ _________
04/05/11 AX745   EM001    CC
04/05/11 AX745   EM005    BK
04/07/11 XY555   EM008    DP

除了用戶ID外，兩個表都包含客戶端ID和某種形式的日期信息。

我還需要引用客戶端ID以獲得實際的客戶端名稱，這些名稱存儲在第三個表中，如下所示：

CLIENTS

CLIENT_ID CLIENT
_________ ________________________
CC        COCA-COLA
KC        KFC
DP        DOMINOS
BK        BURGER KING

我需要一個查詢，該查詢將按每個用戶列表的每個日期返回，該用戶對每個橫幅有多少印象，以及哪個客戶擁有該橫幅，以及該用戶當天發送了多少電子郵件，以及來自哪個客戶。

大概是這樣的：

DATE     USER_ID BANNER_CLIENT_ID BANNER_ID IMPRESSIONS EMAIL_ID EMAIL_CLIENT_ID
________ _______ ________________ _________ ___________ ________ _______________
04/05/11 AX745   COCA-COLA        CC45      4           EM001    COCA-COLA
04/05/11 AX745                                          EM005    BURGER-KING
04/05/11 AX745   KFC              KC66      1
04/07/11 XY555   DOMINOS          DP45      2           EM008    DOMINOS

我可以分別獲取每組信息沒有問題，但是到目前為止，我還無法將所有數據合並到一個報告中。

任何幫助將不勝感激。

謝謝！

C

Answer 1

下面的查詢應為您提供所需的輸出。

SELECT A.DATE, A.USER_ID, A.BANNER_ID, A.IMPRESSIONS, B.EMAIL_ID, C.CLIENT AS EMAIL_CLIENT_ID
FROM BANNERS A
LEFT JOIN EMAILS B ON A.CLIENT_ID=B.CLIENT_ID
LEFT JOIN CLIENTS C ON A.CLIENT_ID=C.CLIENT_ID
WHERE A.DATE=TO_DATE('04/07/11', 'MM-DD-YY')

Answer 2

Declare @impressions table
( [DATE]        date,
  [USER_ID]     varchar(10),
  [CLIENT_ID]   varchar(10),
  [BANNER_ID]   varchar(10),
  [IMPRESSIONS] int
)

Declare @ClientEmails table
( [DATE]        date,
  [USER_ID]     varchar(10),
  [EMAIL_ID]    varchar(10),
  [CLIENT_ID]   varchar(10)
)

Declare @Clients table
(  [CLIENT_ID]   varchar(10),
   [CLIENT]      varchar(50)
)   


Insert Into  @impressions ([DATE], [USER_ID], [CLIENT_ID], [BANNER_ID], [IMPRESSIONS])
Values ('2011/04/05', 'AX745', 'CC', 'CC45', 4),
       ('2011/04/05', 'AX745', 'KC', 'KC66', 1),
       ('2011/04/07', 'XY555', 'DP', 'DP45', 2)


Insert Into  @ClientEmails ([DATE],[USER_ID],[EMAIL_ID], [CLIENT_ID])
Values ('2011/04/05', 'AX745', 'EM001', 'CC'),
       ('2011/04/05', 'AX745', 'EM005', 'BK'),
       ('2011/04/07', 'XY555', 'EM008', 'DP')

Insert Into  @Clients([CLIENT_ID], [CLIENT])
Values ('CC', 'COCA-COLA'),
       ('KC', 'KFC'),
       ('DP', 'DOMINOS'),
       ('BK', 'BURGER KING')


Select isNull(imp.[DATE], eml.[DATE]) as [DATE],
       imp.[USER_ID],
       cli.[CLIENT] as [BANNER_CLIENT_ID],
       imp.[USER_ID] as [BANNER_ID],
       imp.[IMPRESSIONS],
       eml.[EMAIL_ID],
       emc.[CLIENT]  as [EMAIL_CLIENT_ID]
  from @impressions imp
  Left Join @Clients cli 
    on imp.[CLIENT_ID]=cli.[CLIENT_ID]
  Full outer Join @ClientEmails eml 
    on imp.[CLIENT_ID]=eml.[CLIENT_ID] 
   and imp.[USER_ID]=eml.[USER_ID]
   and imp.[DATE]=eml.[DATE]
  Left Join @Clients emc 
    on eml.CLIENT_ID=emc.CLIENT_ID  
 Order By [DATE]

Answer 3

因為您既可以使用沒有電子郵件的橫幅，也可以使用沒有橫幅的電子郵件，那么您將需要使用FULL OUTER JOIN。

SELECT 
  nvl(A.DATE, b.date) as DATE,
  nvl(A.USER_ID, b.user_id) as USER_ID,
  c.client as banner_client_id,
  A.BANNER_ID, 
  A.IMPRESSIONS,  
  B.EMAIL_ID,  
  D.CLIENT AS EMAIL_CLIENT_ID
FROM 
  BANNERS A
  FULL OUTER JOIN EMAILS B ON (A.USER_ID=B.USER_ID AND 
                         a.DATE = b.DATE and
                         A.CLIENT_ID = B.CLIENT_ID)
  LEFT OUTER JOIN CLIENTS C ON (C.CLIENT_ID= a.CLIENT_ID)
  LEFT OUTER JOIN CLIENTS D ON (D.CLIENT_ID= B.CLIENT_ID)

完整的查詢版本包括一些示例數據如下所示：

with banners as (
  select date '2011-04-05' as date_col, 'AX745' as user_id, 'CC' as client_id, 'CC45' as banner_id, 4 as impressions from dual union all
  select date '2011-04-05' as date_col, 'AX745' as user_id, 'KC' as client_id, 'KC56' as banner_id, 1 as impressions from dual union all
  select date '2011-04-07' as date_col, 'XY555' as user_id, 'DP' as client_id, 'CC45' as banner_id, 2 as impressions from dual
),
emails as (
  select date '2011-04-05' as date_col, 'AX745' as user_id, 'EM001' as email_id, 'CC' as client_id from dual union all
  select date '2011-04-05' as date_col, 'AX745' as user_id, 'EM005' as email_id, 'BK' as client_id from dual union all
  select date '2011-04-07' as date_col, 'XY555' as user_id, 'EM008' as email_id, 'DP' as client_id from dual
),
clients as (
  select 'CC' as client_id, 'Coca-Cola' as client_name from dual union all
  select 'KC' as client_id, 'KFC' as client_name from dual union all
  select 'DP' as client_id, 'Dominos' as client_name from dual union all
  select 'BK' as client_id, 'Burger King' as client_name from dual
)
select 
  nvl(A.DATE_col, b.date_col) as DATE_col,
  nvl(A.USER_ID, b.user_id) as USER_ID,
  c.client_name as banner_client_id,
  A.BANNER_ID, 
  A.IMPRESSIONS,  
  B.EMAIL_ID,  
  D.CLIENT_name AS EMAIL_CLIENT_ID
from 
  banners a
  full outer join emails b on (A.USER_ID=B.USER_ID AND 
                         a.DATE_col = b.DATE_col and
                         A.CLIENT_ID = B.CLIENT_ID)
  left outer join clients c on (a.client_id = c.client_id)
  left outer join clients d on (b.client_id = d.client_id)