创建
create [or replace] trggier tri_name [before|after|instead of] tri_event on table_name|view_name|user_name|db_name [for each row|when tri_condition] begin plsql_sentences; end tri_name;
示例
Trigger 触发器
原文：http://www.cnblogs.com/cnblogs-qm/p/7083114.html
