SQL - データの生成、変換、操作(数値)

開発環境

• OS: OS X Lion - Apple
• データベース言語: SQL
• リレーショナルデータベース: MySQL

『初めてのSQL』(Alan Beaulieu 著、株式会社クイープ 翻訳、オライリー・ジャパン、2006年、ISBN4-87311-281-8) の7章(データの生成、変換、操作),　7.5(練習問題)7-2を解いてみる。

7-2.

入出力結果(Terminal)

$ mysql -u lrngsql -p
Enter password: 
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 1
Server version: 5.5.18 MySQL Community Server (GPL)

Copyright (c) 2000, 2011, Oracle and/or its affiliates. All rights reserved.

Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

mysql> select abs(-25.76823)
    -> ;
+----------------+
| abs(-25.76823) |
+----------------+
|       25.76823 |
+----------------+
1 row in set (0.03 sec)

mysql> select sign(-25.76823);
+-----------------+
| sign(-25.76823) |
+-----------------+
|              -1 |
+-----------------+
1 row in set (0.01 sec)

mysql> select round(-25.75823,2);
+--------------------+
| round(-25.75823,2) |
+--------------------+
|             -25.76 |
+--------------------+
1 row in set (0.00 sec)

mysql> quit
Bye
$