��졼����ʥ� �ǡ����١����Ȥ�

�̤���

 lastname | firstname |    born    |   pref   | bloodtype | musu_id
----------+-----------+------------+----------+-----------+---------
 ����     | �¿�      | 1981-08-08 | �̳�ƻ   | A         |       1
 ����     | �ʤĤ�    | 1981-08-10 | �̳�ƻ   | A         |       2
 ����     | ��        | 1980-12-06 | �̳�ƻ   | A         |       3
 ���     | ��Τ      | 1983-01-20 | ���ո�   | A         |       4
                                                                  |
                 +------------------------------------------------+
                 v
 moni_id | musu_id
---------+---------
       1 |       1
       1 |       2
       3 |       3
       ^
       +---------------+
                       |
      name      | moni_id
----------------+---------
 �⡼�˥�̼�� |       1
 �ߥ˥�ˡ�     |       2
 �ץå����     |       3

�֥ץå���ˡ�����������̾����շ��� ɽ������ SQL (Structured Query Language)

SELECT musu.lastname, musu.firstname, musu.bloodtype
  FROM musu, moni, member
 WHERE member.moni_id = moni.moni_id 
   AND member.musu_id = musu.musu_id
       AND moni.name = '�ץå����';

�䤤��碌�η�� 

 lastname | firstname | bloodtype
----------+-----------+-----------
 ����     | ��        | A
 ��ƣ     | ����      | O
 ��߷     | �ҤȤ�    | O
(3 rows)

WWW ����ǡ����١��������Ѥ��롣

http://www.lab.tkikuchi.net/~tkikuchi/mm/