MySQL Triggers

[uniquejava]

Introduction to MySQL AFTER UPDATE triggers

不能像oracle那样

unfortunately we can't use in MySQL after INSERT or UPDATE description, like in Oracle

MySQL Fire Trigger for both Insert and Update

cyper 实战

# drop trigger ON_GRADE_UPDATE;
create trigger ON_GRADE_UPDATE
 after update
 on customer
 for each row

begin
 if old.grade <> new.grade THEN
 insert into event(event_title, event_description, start_date, end_date, start_time, end_time,
 is_full_day_event,
 is_recurring, created_by,
 created_at, parent_event_id)
 values ('customer grade changed!', concat('from ', old.grade, ' to ', new.grade), now(), null,
 null, null, 'N', 'N', 'cyper', now(), null);
 end if;

end;

drop trigger if exists comment_count_changes;
create trigger comment_count_changes
 after insert
 on cms_comment
 for each row
begin
 select t.created_by, t.title into @author, @title from cms_post t where id = new.post_id;

 if @author = 2 then
 insert into event(event_title, event_description, start_date, end_date, start_time, end_time,
 is_full_day_event,
 is_recurring, created_by,
 created_at, parent_event_id)
 values (@title, concat('刚有人回复了你的帖子:', new.body), now(), null,
 null, null, 'N', 'N', 'cyper', now(), null);
 end if;

end;