SQL - クエリ入門(エイリアス、テーブルリンク)

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3章(クエリ入門),　3.8(練習問題)3-4.を解いてみる。

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 7
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> show databases;
+--------------------+
| Database           |
+--------------------+
| information_schema |
| bank               |
| mysql              |
| performance_schema |
| sample_store       |
| store              |
| test               |
+--------------------+
7 rows in set (0.37 sec)

mysql> use bank;
Reading table information for completion of table and column names
You can turn off this feature to get a quicker startup with -A

Database changed
mysql> show tables;
+----------------+
| Tables_in_bank |
+----------------+
| account        |
| branch         |
| business       |
| customer       |
| department     |
| employee       |
| favorite_food  |
| individual     |
| officer        |
| person         |
| product        |
| product_type   |
| transaction    |
+----------------+
13 rows in set (0.00 sec)

mysql> desc product;
+-----------------+-------------+------+-----+---------+-------+
| Field           | Type        | Null | Key | Default | Extra |
+-----------------+-------------+------+-----+---------+-------+
| product_cd      | varchar(10) | NO   | PRI | NULL    |       |
| name            | varchar(50) | NO   |     | NULL    |       |
| product_type_cd | varchar(10) | NO   | MUL | NULL    |       |
| date_offered    | date        | YES  |     | NULL    |       |
| date_retired    | date        | YES  |     | NULL    |       |
+-----------------+-------------+------+-----+---------+-------+
5 rows in set (0.01 sec)

mysql> desc account;
+--------------------+----------------------------------+------+-----+---------+----------------+
| Field              | Type                             | Null | Key | Default | Extra          |
+--------------------+----------------------------------+------+-----+---------+----------------+
| account_id         | int(10) unsigned                 | NO   | PRI | NULL    | auto_increment |
| product_cd         | varchar(10)                      | NO   | MUL | NULL    |                |
| cust_id            | int(10) unsigned                 | NO   | MUL | NULL    |                |
| open_date          | date                             | NO   |     | NULL    |                |
| close_date         | date                             | YES  |     | NULL    |                |
| last_activity_date | date                             | YES  |     | NULL    |                |
| status             | enum('ACTIVE','CLOSED','FROZEN') | YES  |     | NULL    |                |
| open_branch_id     | smallint(5) unsigned             | YES  | MUL | NULL    |                |
| open_emp_id        | smallint(5) unsigned             | YES  | MUL | NULL    |                |
| avail_balance      | float(10,2)                      | YES  |     | NULL    |                |
| pending_balance    | float(10,2)                      | YES  |     | NULL    |                |
+--------------------+----------------------------------+------+-----+---------+----------------+
11 rows in set (0.01 sec)

mysql> select p.product_cd,a.cust_id,a.avail_balance
    -> from product p inner join account a
    -> on p.product_cd = a.product_cd
    -> where p.product_type_cd;
Empty set, 8 warnings (0.14 sec)

mysql> select p.product_cd,a.cust_id,a.avail_balance from product p inner join account a on p.product_cd = a.product_cd where p.product_type_cd=='ACCOUNT';
ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '=='ACCOUNT'' at line 1
mysql> select p.product_cd,a.cust_id,a.avail_balance from product p inner join account a on p.product_cd = a.product_cd where p.product_type_cd='ACCOUNT';
+------------+---------+---------------+
| product_cd | cust_id | avail_balance |
+------------+---------+---------------+
| CD         |       1 |       3000.00 |
| CD         |       6 |      10000.00 |
| CD         |       7 |       5000.00 |
| CD         |       9 |       1500.00 |
| CHK        |       1 |       1057.75 |
| CHK        |       2 |       2258.02 |
| CHK        |       3 |       1057.75 |
| CHK        |       4 |        534.12 |
| CHK        |       5 |       2237.97 |
| CHK        |       6 |        122.37 |
| CHK        |       8 |       3487.19 |
| CHK        |       9 |        125.67 |
| CHK        |      10 |      23575.12 |
| CHK        |      12 |      38552.05 |
| MM         |       3 |       2212.50 |
| MM         |       4 |       5487.09 |
| MM         |       9 |       9345.55 |
| SAV        |       1 |        500.00 |
| SAV        |       2 |        200.00 |
| SAV        |       4 |        767.77 |
| SAV        |       8 |        387.99 |
+------------+---------+---------------+
21 rows in set (0.44 sec)

mysql> quit;
Bye
$

まだ超スローペース。だけど3章終了。