$ lynx http://www.naver.com

# cp 명령어의 매뉴얼을 확인 
$ man mv

MV(1)                           General Commands …

Input: 
Visits
+----------+-------------+
| visit_id | customer_id |
+----------+-------------+
| 1        | 23          |
| 2        | 9           |
| 4        | 30          |
| 5        | 54          |
| 6        | 96          |
| 7        | 54          |
| 8        | 54          |
+----------+-------------+
visit_id is the primary key for this table.
This table contains information about the customers who visited the mall.

Transactions
+----------------+----------+--------+
| transaction_id | visit_id | amount |
+----------------+----------+--------+
| 2              | 5        | 310 …

-- 1위 한 명만
SELECT o.customer_number
FROM orders o 
GROUP BY o.customer_number 
ORDER BY COUNT …

[begin_label:] BEGIN
    [statement_list]
END [end_label]

CASE case_value
    WHEN when_value THEN statement_list
    [WHEN when_value THEN statement_list] ...
    [ELSE statement_list]
END CASE

CASE
    WHEN search_condition THEN statement_list
    [WHEN search_condition THEN statement_list] ...
    [ELSE statement_list]
END CASE

Input: 
Users table:
+---------+-------+
| user_id | name  |
+---------+-------+
| 1       | aLice |
| 2       | bOB   |
+---------+-------+
user_id is the primary key for this table.
This table contains the ID and the name of the user. The name consists of only lowercase and uppercase characters.

Output: 
+---------+-------+
| user_id | name  |
+---------+-------+
| 1       | Alice |
| 2       | Bob …