四個字 堅持到底

trigger內容
不能INSERT,UPDATE原本有更動,而造成trigger的table
即使是原本table有select table A,也不能對table A 做以上動作

MySQL Triggers Tutorial
On an INSERT, you can only use NEW for column values. On a DELETE, you must use OLD.
other ref:
http://www.roseindia.net/mysql/mysql5/triggers.shtml
http://www.rustyrazorblade.com/index.php/2006/09/14/mysql-triggers-tutorial/

1.兩個關聯table必須是InnoDB type
2.使用foreign key的鍵必須是index
3.使用foreign key必須與原鍵類型相同

DBDesigner 4
http://fabforce.net/dbdesigner4/index.php
MySQL Workbench
http://www.mysql.com/products/tools/workbench/
網路上找到的,試試看

mysql> SELECT something FROM table
           WHERE TO_DAYS(NOW()) - TO_DAYS(date_col) <= 30;
from:MySQL中文參考手冊:7.4.11 日期和時間函數