特简单的菜鸟问题：这个MS SQL触发器转到oracle该怎么写呢

Question

CREATE  TRIGGER  ZYDJB_DEL  
before delete on ZYDJB 
FOR each row
declare
num number;
begin
select count(1) into num from ZYQKCXB where ZYBS=:old.ZYBS;
if num>0 then
  DELETE FROM ZYQKCXB
  WHERE ZYBS=:old.ZYBS;
  DELETE FROM ZYSHSXB
  WHERE ZYBS=:old.ZYBS;
                                          DELETE FROM LJZYCXB
  WHERE ZYBS=:old.ZYBS ;
                                      DELETE FROM ZYDJGXB
  WHERE ZYBS=:old.ZYBS
                                             OR
                                          SCZYBS=:old.ZYBS;
     
 END;

Answer 1

CREATE or replace TRIGGER  ZYDJB_DEL  
before delete on ZYDJB 
FOR each row
declare
num number;
begin
select count(1) into num from ZYQKCXB where ZYBS=:old.ZYBS;
if num>0 then
  DELETE FROM ZYQKCXB
  WHERE ZYBS=:old.ZYBS;
  DELETE FROM ZYSHSXB
  WHERE ZYBS=:old.ZYBS;
                                          DELETE FROM LJZYCXB
  WHERE ZYBS=:old.ZYBS ;
                                      DELETE FROM ZYDJGXB
  WHERE ZYBS=:old.ZYBS
                                             OR
                                          SCZYBS=:old.ZYBS;
     
 END;

Answer 2

@@ROWCOUNT>1
这个条件怎么加呢？