觸發功能

Question

我嘗試做一個觸發功能，將檢查是否在插入/事件日期的記錄的更新的信息是有效的：

create or replace function trigf() returns trigger as $$ 
declare bad_date record; 
begin 
    select festival.title into bad_date 
    from festival 
    where new.title = festival.title and (new.edate < festival.sdate or new.edate > festival.edate); 

    if exists bad_date then 
       raise notice 'Error: Event Date does not Correlate with the Festival.'; 
       if T = 'insert' then return null; 
        else return old; 
         end if; 
     else 
      return new; 
     end if; 
end; 
$$language plpgsql; 

create trigger T 
before insert or update on event 
for each row 
execute procedure trigf(); 

編譯通過罰款，但試圖插入值時，我得到bad_date不存在的錯誤。我想誰並欣賞熱門知道任何人去修補，而不是它

Answer 1

：

declare bad_date record; 

if exists bad_date then 

應該是：

declare bad_date text; -- or same type of festival.title 

if bad_date IS NOT NULL then