Question

我正在尝试编写一个触发器和一个更新namespace FoodOrderingApp { public sealed partial class MainPage : Page { public MainPage() { this.InitializeComponent(); this.NavigationCacheMode = NavigationCacheMode.Required; } protected override void OnNavigatedTo(NavigationEventArgs e) { } private void btnRegister_Click(object sender, RoutedEventArgs e) { Frame.Navigate(RegisterPage)); } }表的函数。触发器必须仅在包含常规＆＃39;的新值时才会拍摄。在pricing列插入/更新：

offer

问题：当我运行此查询时：

drop trigger if exists reduced_offer on pricing;
drop function if exists offer_f();

create or replace function offer_f() returns trigger as $$
begin
    if (new.title, new.publisher,new.offer) in  --the offer already EXISTS
        (select title, publisher, offer
        from pricing)
    then
        raise notice 'exists';
        update pricing
        set price=new.price*0.9
        where title=new.title and publisher=new.publisher and period=new.period;
    else                        --the offer does NOT EXIST
        raise notice 'not exists';
        insert into pricing values
            (new.title, new.publisher, 'renew', new.period, new.price*0.9);
    end if; 

    return null;
end $$ language plpgsql;


create trigger reduced_offer 
after insert or update 
on pricing
for each row
when (new.offer='regular')
execute procedure offer_f();

当我确定此条目不在insert into pricing values ('Nature', 'UCLA', 'regular', 9900, 20);表中时，我得到堆栈溢出错误和ENDLESS输出（超过20000行）：

通知：存在

通知：存在

CONTEXT：SQL语句＆＃34;更新定价
pricing
period = new.period

并提供=＆＃39;常规＆＃39;＆＃34;

PL / pgSQL函数offer_f（）在SQL语句第8行

通知：存在

CONTEXT：SQL语句＆＃34;更新定价
  set price=new.price*0.9

  where title=new.title and publisher=new.publisher and
period = new.period

依旧......

知道什么会导致这种溢出吗？

在SQL中执行触发器函数时防止出现rucedive触发

0 个答案: