SQL CASE Statement

Giả sử ta có bảng sau :)))
mysql> SELECT customerNumber, customerName FROM customers;
+----------------+------------------------------------+
| customerNumber | customerName                       |
+----------------+------------------------------------+
|            462 | FunGiftIdeas.com                   |
|            465 | Anton Designs, Ltd.                |
|            471 | Australian Collectables, Ltd       |
|            473 | Frau da Collezione                 |
|            475 | West Coast Collectables Co.        |
|            477 | Mit Vergnügen & Co.                |
|            480 | Kremlin Collectables, Co.          |
|            481 | Raanan Stores, Inc                 |
|            484 | Iberia Gift Imports, Corp.         |
|            486 | Motor Mint Distributors Inc.       |
|            487 | Signal Collectibles Ltd.           |
|            489 | Double Decker Gift Stores, Ltd     |
|            495 | Diecast Collectables               |
|            496 | Kelly's Gift Shop                  |
+----------------+------------------------------------+
Giờ ta sử dụng câu lệnh sau để sử dụng lẹnh CASE cho cột  customerNumber
mysql> SELECT customerNumber, customerName, CASE  
    -> WHEN customerNumber > 460 && customerNumber < 470 THEN ">460 && < 470"
    -> WHEN customerNumber = 470 THEN "470"
    -> WHEN customerNumber > 470 THEN ">470"
    -> END AS custom 
    -> FROM customers;
Kết quả:
+----------------+------------------------------------+---------------+
| customerNumber | customerName                       | custom        |
+----------------+------------------------------------+---------------+
|            462 | FunGiftIdeas.com                   | >460 && < 470 |
|            465 | Anton Designs, Ltd.                | >460 && < 470 |
|            471 | Australian Collectables, Ltd       | >470          |
|            473 | Frau da Collezione                 | >470          |
|            475 | West Coast Collectables Co.        | >470          |
|            477 | Mit Vergnügen & Co.                | >470          |
|            480 | Kremlin Collectables, Co.          | >470          |
|            481 | Raanan Stores, Inc                 | >470          |
|            484 | Iberia Gift Imports, Corp.         | >470          |
|            486 | Motor Mint Distributors Inc.       | >470          |
|            487 | Signal Collectibles Ltd.           | >470          |
|            489 | Double Decker Gift Stores, Ltd     | >470          |
|            495 | Diecast Collectables               | >470          |
|            496 | Kelly's Gift Shop                  | >470          |
+----------------+------------------------------------+---------------+