SQL SELECT從一列和輸出SQL重複值的多個列

Question

專業表有很多列FIRST_NAME，MIDDLE_NAME，姓氏，TITLE_CODE，COMMUNICATION_TYPE_CODE，COMMUNICATION_VALUE

PROFESSIONAL Table 


COMMUNICATION_TYPE_CODE column     
Telephone                
Telephone                
Fax              
Fax             
E-mail             
E-mail             
Cellular            
Cellular            

COMMUNICATION_VALUE column 
224-256-5689 
547-568-5642 
254-565-4526 
524-465-6542 
jones@gmail.com 
james@yahoo.com 
562-564-7854 
654-452-6897 

這僅僅是一個樣品。有500,00記錄，像這樣COMMUNICATION_TYPE_CODE和COMMUNICATION_VALUE列

Telephone = PHONE1 
Cellular = PHONE2 
E-mail = EMAIL1 
Fax = FAX1 



SELECT 'IMD Data Source' as DATA_SOURCE, 
FIRST_NAME as FIRST_NM, 
MIDDLE_NAME as MIDDLE_NM, 
LAST_NAME as LAST_NM, 
TITLE_CODE as CREDENTIALS, 
PHONE1, 
PHONE2, 
EMAIL1, 
FAX1, 
FROM DLA_PROFESSIONAL_A 

I already mapped the FIRST_NAME,MIDDLE_NAME, LAST_NAME, TITLE_CODE to target columns in my select statement so dont worry about that. I am having problems mapping PHONE1,PHONE2,EMAIL1,FAX1 

我要挑出來的通信值列數據（電話號碼，電子郵件，傳真，蜂窩）當交際類型代碼是（電話，傳真，電子郵件，蜂窩）

這具有去4個獨立COLUMNS（當COMMUNICATION_TYPE_CODE =「電話」我需要從柱拉COMMUNICATION_VALUE數據和其映射到 PHONE1列輸出，當COMMUNICATION_TYPE_CODE ='蜂窩'我需要從列中提取COMMUNICATION_VALUE數據，並將其映射到 PHONE2列的輸出中，當COMMUNICATION_TYPE_CODE ='電子郵件'我需要從柱拉COMMUNICATION_VALUE數據和其映射到在輸出 EMAIL1柱，當COMMUNICATION_TYPE_CODE =「傳真」我需要從柱拉COMMUNICATION_VALUE數據和其映射到在輸出 EMAIL1列）

I have the separate sequels I dont know how to put it in to the original select statement. 




SELECT DISTINCT COMMUNICATION_VALUE FROM DG_SP_NP.DLA_PROFESSIONAL_A WHERE COMMUNICATION_TYPE_CODE='Telephone' 

SELECT DISTINCT COMMUNICATION_VALUE FROM DG_SP_NP.DLA_PROFESSIONAL_A WHERE COMMUNICATION_TYPE_CODE='Cellular' 

SELECT DISTINCT COMMUNICATION_VALUE FROM DG_SP_NP.DLA_PROFESSIONAL_A WHERE COMMUNICATION_TYPE_CODE='E-mail' 

SELECT DISTINCT COMMUNICATION_VALUE FROM DG_SP_NP.DLA_PROFESSIONAL_A WHERE COMMUNICATION_TYPE_CODE='Fax' 

我想要做這樣的事情。這不是4個輸出的正確的sql，但你明白了。

SELECT 'IMD Data Source' DATA_SOURCE, 
FIRST_NAME as FIRST_NM, 
MIDDLE_NAME as MIDDLE_NM, 
LAST_NAME as LAST_NM, 
TITLE_CODE as CREDENTIALS, 
SELECT DISTINCT COMMUNICATION_VALUE FROM PROFESSIONAL WHERE COMMUNICATION_TYPE_CODE='Telephone' as PHONE1, 
SELECT DISTINCT COMMUNICATION_VALUE FROM PROFESSIONAL WHERE COMMUNICATION_TYPE_CODE='Cellular' as PHONE2, 
SELECT DISTINCT COMMUNICATION_VALUE FROM PROFESSIONAL WHERE COMMUNICATION_TYPE_CODE='E-mail' as EMAIL1, 
SELECT DISTINCT COMMUNICATION_VALUE FROM PROFESSIONAL WHERE COMMUNICATION_TYPE_CODE='Fax' as FAX1, 
FROM PROFESSIONAL 

所有數據都在一個表（專業人士）

Answer 1

你在做什麼是相當複雜的。您正嘗試單獨訂購聯繫信息。 SQL並不完全支持這一點。

相反，您需要添加一個「行號」列，在下面的代碼中稱爲seqnum。該查詢使用此信息將聯繫信息組合到適當的行上。我發現聯合和組合方法更容易（替代方法是全外連接）。

select p.<whatever>, phone1, phone2, EmailContacts, fax 
from Professional p left outer join 
    (select ProfessionalId, seqnum, 
      MAX(Phone1) as Phone1, MAX(Phone2) as Phone2, MAX(Email) as Email, MAX(Fax) as fax 
     from ((select ProfessionalId, COMMUNICATION_VALUE as Phone1, 
        NULL as Phone2, NULL as Email, NULL as Fax 
        row_number() over (partition by ProfessionalId order by ProfessionalId) as seqnum 
      from (select distinct ProfessionalId, COMMUNICATION_VALUE, 
        from Professional p 
        where COMMUNICATION_TYPE_CODE = 'Telephone' 
       ) 
      ) union all 
      (select ProfessionalId, NULL, COMMUNICATION_VALUE, NULL, NULL 
        row_number() over (partition by ProfessionalId order by ProfessionalId) as seqnum 
      from (select distinct ProfessionalId, COMMUNICATION_VALUE, 
        from Professional p 
        where COMMUNICATION_TYPE_CODE = 'Cellular' 
       ) 
      ) union all 
      (select ProfessionalId, NULL, NULL, COMMUNICATION_VALUE, NULL 
        row_number() over (partition by ProfessionalId order by ProfessionalId) as seqnum 
      from (select distinct ProfessionalId, COMMUNICATION_VALUE, 
        from Professional p 
        where COMMUNICATION_TYPE_CODE = 'E-mail' 
       ) 
      ) union all 
      (select ProfessionalId, NULL, NULL, NULL, COMMUNICATION_VALUE, 
        row_number() over (partition by ProfessionalId order by ProfessionalId) as seqnum 
      from (select distinct ProfessionalId, COMMUNICATION_VALUE, 
        from Professional p 
        where COMMUNICATION_TYPE_CODE = 'Fax' 
       ) 
      ) 
      ) 
    group by ProfessionalId, seqnum 
    ) c 
    on c.ProfessionalId = p.ProfessionalId 

此查詢假定每行都有一個ProfessionalId來標識每個人。

Answer 2

那是不可能的。

我假設你有這樣的：

JIM | SMITH | TELEPHONE | 224-256-5689 
JIM | SMITH | TELEPHONE | 547-568-5642 

一個（不同的）吉姆·史密斯一行必須如何知道哪個communication_values的返回時，有不止一個？

您可以獲得> 1行，或者您需要選擇TOP 1或某些其他條件來返回所需的單個值。

也許你想這樣的事情作爲你的嵌套查詢：

(SELECT TOP 1 COMMUNICATION_VALUE FROM PROFESSIONAL P_INNER WHERE COMMUNICATION_TYPE_CODE='Telephone' AND P_INNER.<field/s> = P_OUTER.<field/s> ORDER BY <some_field>) 

編輯

的這樣呢？

CASE WHEN COMMUNICATION_TYPE_CODE='Telephone' THEN COMMUNICATION_VALUE END as PHONE1, 
CASE WHEN COMMUNICATION_TYPE_CODE='Cellular' THEN COMMUNICATION_VALUE END as PHONE2, 
CASE WHEN COMMUNICATION_TYPE_CODE='E-mail' THEN COMMUNICATION_VALUE END as EMAIL1, 
CASE WHEN COMMUNICATION_TYPE_CODE='Fax' THEN COMMUNICATION_VALUE END as FAX1, 

Answer 3

關係表中的列只能包含一個值。這意味着根據您提供的模式（列名稱），PROFESSIONAL表的每個條目只能有一個用於COMMUNICATION_CODE的值和一個用於COMMUNICATION_VALUE的值。在關係數據庫術語中，這被稱爲First Normal Form。

這就是說，您可以在PROFESSIONAL表中有多個條目，每個條目都具有相同的名稱信息，但具有唯一的COMMUNICATION_VALUE和COMMUNICAITON_CODE數據。但是，這違反了另一個關係設計考慮，即儘量減少數據重複。

我的建議是將COMMUNICATION_VALUE和COMMUNICATION_CODE置於一個單獨的表中，然後使用PROFESSIONAL表的主鍵作爲此新通信表的輔助鍵，以便能夠爲每個條目選擇所有COMMUNICATION TABLE值PROFESSIONAL表。

這有道理嗎？