SQL - 集約関数(数値データの操作(集合内の値の数(count()))

初めてのSQL
Alan Beaulieu (著)

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8章(集約関数),　8.5(練習問題)8-1を解いてみる。

8-1.

入出力結果(Terminal)

$ mysql -u lrngsql -p bank;
Enter password: 
Reading table information for completion of table and column names
You can turn off this feature to get a quicker startup with -A

Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 1
Server version: 5.5.24 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 count(*) from account;
+----------+
| count(*) |
+----------+
|       24 |
+----------+
1 row in set (0.00 sec)

mysql> quit;
Bye
$