oracle 触发器

参考大神们网址：

https://www.cnblogs.com/sharpest/p/7764662.html

https://www.cnblogs.com/sharpest/p/7764662.html

https://www.cnblogs.com/wishyouhappy/p/3665851.html

自己写的实例：(每次实时数据表插入新记录时，在table_b表中放入一条数据，放入的是刚插入实时表的一部分数据。

                          同时只保留table_b中最近十条数据。

                          注：如果begin中语句有错误会对触发表（ta_realdata）中数据产生影响。)

create or replace trigger chart_data
after insert on ta_realdata
for each row
begin
insert into ta_b
values
(:NEW.MONITOR_ID,
:NEW.name,
:NEW.code,
:NEW.MONITOR_TIME);

delete from ta_b
where ta_b.monitor_id in
(SELECT B.monitor_id
FROM (SELECT A.*, ROWNUM RN
FROM (select ta_b.monitor_id, MONITOR_TIME
from ta_b
where ta_b.code =:NEW.CODE
order by MONITOR_TIME desc
) A) B
WHERE RN > 10) ;
END;

删除触发器：

DROP TRIGGER chart_data;