根據第三列中的類型代碼將列拆分爲兩列

Question

我的SQL非常生鏽。我試圖改變這個表：

+----+-----+--------------+-------+ 
| ID | SIN | CONTACT | TYPE | 
+----+-----+--------------+-------+ 
| 1 | 737 | b@bacon.com | email | 
| 2 | 760 | 250-555-0100 | phone | 
| 3 | 737 | 250-555-0101 | phone | 
| 4 | 800 | 250-555-0102 | phone | 
| 5 | 850 | l@lemon.com | email | 
+----+-----+--------------+-------+ 

到這個表：

+----+-----+--------------+-------------+ 
| ID | SIN | PHONE  | EMAIL | 
+----+-----+--------------+-------------+ 
| 1 | 737 | 250-555-0101 | b@bacon.com | 
| 2 | 760 | 250-555-0100 |    | 
| 4 | 800 | 250-555-0102 |    | 
| 5 | 850 |    | l@lemon.com | 
+----+-----+--------------+-------------+ 

我寫此查詢：

SELECT * 
    FROM (SELECT * 
      FROM people 
     WHERE TYPE = 'phone') phoneNumbers 
     FULL JOIN (SELECT * 
        FROM people 
        WHERE TYPE = 'email') emailAddresses 
      ON phoneNumbers.SIN = emailAddresses.SIN; 

主要生產：

+----+-----+--------------+-------+------+-------+-------------+--------+ 
| ID | SIN | CONTACT | TYPE | ID_1 | SIN_1 | CONTACT_1 | TYPE_1 | 
+----+-----+--------------+-------+------+-------+-------------+--------+ 
| 2 | 760 | 250-555-0100 | phone |  |  |    |  | 
| 3 | 737 | 250-555-0101 | phone | 1 | 737 | b@bacon.com | email | 
| 4 | 800 | 250-555-0102 | phone |  |  |    |  | 
| |  |    |  | 5 | 850 | l@lemon.com | email | 
+----+-----+--------------+-------+------+-------+-------------+--------+ 

我知道我可以選擇我想要的列，bu SIN列不完整。我似乎記得，我應該第三次加入表格來獲得完整的SIN列，但我不記得如何。

如何生成我的目標表（ID，SIN，PHONE，EMAIL）？

編輯和澄清：我非常感謝迄今爲止收到的答案，但作爲一個SQL新手，我不熟悉您正在使用的技術（case語句，條件聚合和透視）。這不能使用JOIN和SELECT來完成嗎？請原諒我對這件事的無知。 （這並不是說我不感興趣的卓越技術，但我不想太快太早移動。）接近，這是有條件的聚集

Answer 1

方式一：

select min(ID), SIN, 
     max(case when type = 'phone' then contact end) as phone, 
     max(case when type = 'email' then contact end) as email 
from people t 
group by sin; 

Answer 2

似乎是一個pivot（神諭.com）在這裏很容易工作。

SELECT ID, SIN, PHONE, EMAIL 
FROM PEOPLE 
PIVOT (
    MAX(CONTACT) 
    FOR TYPE IN ('EMAIL', 'PHONE') 
) 

Answer 3

我意識到這是比張貼的所有解決方案不太優雅，但在這裏它是無論如何，只使用JOIN，然後選擇一個解決方案：

SELECT sins.SIN, phone, email 
    FROM ((SELECT SIN email_sin, contact email 
      FROM people 
      WHERE TYPE = 'email') email 
     FULL JOIN (SELECT SIN phone_sin, contact phone 
        FROM people 
        WHERE TYPE = 'phone') phone 
      ON email.email_sin = phone.phone_sin) 
     RIGHT JOIN (SELECT DISTINCT SIN FROM people) sins 
      ON sins.SIN = phone_sin OR sins.SIN = email_sin; 

這缺少ID列。