insert 触发器示例
将新增的数据放到histotry历史表中:
CREATE TRIGGER [dbo].[insert_lib_items] ON [dbo].[lib_items] AFTER INSERT AS BEGIN insert into his_lib_items( operation_date, perform_id, value, point ) select getdate() as operation_date ,operation_date, perform_id, value, point from inserted END
update触发器示例
将修改前的数据放到histotry历史表中:(注意,这里使用from DELETED,得到的是修改前的数据,若使用inserted将得到修改后的数据)
CREATE TRIGGER [dbo].[update_lib_items] ON [dbo].[lib_items] AFTER UPDATE AS BEGIN insert into his_lib_items( operation_date,perform_id, value, point ) select getdate() as operation_date,perform_id, value, point from DELETED END
delete触发器示例
将删除的数据放到histotry历史表中(注意,这里from DELETED 将得到被删除的数据):
CREATE TRIGGER [dbo].[delete_lib_items] ON [dbo].[lib_items] AFTER DELETE AS BEGIN insert into his_lib_items( operation_date,perform_id, value, point ) select getdate() as operation_date,perform_id, value, point from DELETED END
总结:
当对某张表建立触发器后,分3种情况讨论
1.插入操作(Insert)
Inserted表有数据,Deleted表无数据
2.删除操作(Delete)
Inserted表无数据,Deleted表有数据
3.更新操作(Update)
Inserted表有数据(新数据),Deleted表有数据(旧数据)