触发器实例

前提有总表分表
--------------------------------------------------------------------------------------------------------------------------------------
insert 触发器
create trigger insert_trigger after insert on blog for each row
begin
if new.userid % 3 = 0 then
    insert into blog_0(id,title,content,userid,pubtime) value(new.id,new.title,new.content,new.userid,new.pubtime);
elseif new.userid % 3 = 1 then
    insert into blog_1(id,title,content,userid,pubtime) value(new.id,new.title,new.content,new.userid,new.pubtime);
elseif new.userid % 3 = 2 then
    insert into blog_2(id,title,content,userid,pubtime) value(new.id,new.title,new.content,new.userid,new.pubtime);

end if;
end//

insert into blog(id,title,content,userid,pubtime) value('111','134','789','456','123');

--------------------------------------------------------------------------------------------------------------------------------------
delete 触发器
create trigger delete_trigger after delete  on blog for each row
begin
if old.userid % 3 = 0 then
    delete from blog_0 where id=old.id;
    
elseif old.userid % 3 = 1 then
    delete from blog_1 where id=old.id;

elseif old.userid % 3 = 2 then
    delete from blog_2 where id=old.id;

end if;
end//

delete from blog where id = 111;

--------------------------------------------------------------------------------------------------------------------------------------
update 触发器
create trigger update_trigger after update  on blog for each row
begin
if old.userid % 3 = 0 then
    update  blog_0 set  title = new.title, content=new.content  where id=old.id;
    
elseif old.userid % 3 = 1 then
    update  blog_1 set  title = new.title, content=new.content  where id=old.id;

elseif old.userid % 3 = 2 then
    update  blog_2 set  title = new.title, content=new.content  where id=old.id;

end if;
end//

update blog set title="abc",content="ccc" where id= 112//