PostgreSQL-function、trigger

增長一個自動記錄更新時間的觸發器，

第一步，先寫一個函數，返回觸發器類型的

create function spam_keyword_update_trigger()
returns trigger as 
$$
begin
NEW.tm_update := current_timestamp(0);
return new;
end;
$$
language plpgsql;

第二步，添加調用函數的觸發器，在這裏我把觸發器名稱和函數名稱設爲同樣的

create trigger spam_keyword_update_trigger before update on spam_keyword 
for each row execute procedure spam_keyword_update_trigger();

 

瞭解一張表有哪些觸發器

\d table_name

瞭解觸發器所引用函數的定義

\sf function_name

瞭解一共有哪些本身可見的函數

\df

 

 

行類型
create or replace function thaha(ooo website)returns text as $$
declare
t2_row record;
BEGIN
select into t2_row gid from board where fid=52163;
-- RAISE EXCEPTION 'employee % not found', ooo.name;
return ooo||ooo.url||t2_row.gid;
END;
$$language plpgsql;

select thaha(website) from website  where fid=52163



create or replace function funcx1() returns setof text as $$
declare
i spam_keyword.word%type;
o text ;
begin
for i in select kid from spam_keyword loop
o:=i;
return next o;
end loop;
end;
$$language plpgsql;

select funcx1()
drop function funcx1()