如何在oracle中调用触发函数

Question

如何在oracle中调用单独的触发函数。我了解在postgres中，调用触发函数的语法为

create OR replace trigger_test 
after update or delete on person_info 
FOR EACH ROW EXECUTE FUNCTION trig_function();

同样在postgres中，我可以在函数trig_function（）中获得表person_info的所有旧值和新值。

有没有一种方法可以在oracle中模拟相同的东西，因为我发现了有关触发器的文档与postgres触发器的对比。

Answer 1

在Oracle中，触发器是由标题（CREATE OR REPLACE TRIGGER...）和PL / SQL块组成的整体条目，在发生触发事件时将调用该块。一个例子是：

CREATE OR REPLACE TRIGGER EMPLOYEES_BIU
  BEFORE INSERT OR UPDATE ON EMPLOYEES
  FOR EACH ROW
DECLARE                    -- This is only included to demonstrate that 
  nSome_variable  NUMBER;  -- you can include a DECLARE section.
BEGIN                      
  IF INSERTING THEN
    :NEW.ADD_DATE := SYSDATE;
    :NEW.ADD_USER := UID;
  ELSIF UPDATING THEN
    :NEW.ADD_DATE := :OLD.ADD_DATE;
    :NEW.ADD_USER := :OLD.ADD_USER;
    :NEW.MTC_DATE := SYSDATE;
    :NEW.MTC_USER := UID;
  END IF;
END EMPLOYEES_BIU;

旧值和新值可通过伪行:OLD和:NEW获得。

Answer 2

我希望您尝试从触发器内调用函数。如果是这种情况，那么您可以执行类似的操作

create or replace trigger trigger_test
after update or delete on person_info 
for each row
declare
c_person person_info<specify your type>%TYPE
begin
if trig_function(:NEW.person) != c_person; -- not sure what your function returns
--your logic here

end if;
end; 
/

或者您可以做类似的事情>>

create or replace trigger trigger_test
    after update or delete on person_info 
    for each row
    begin
   if trig_function(:NEW.person) != "ABC"  ---- not sure what your function returns
   ----implement your logic with the function

   end if;
    end; 
    /