sql多表查询用一句话输出

刚开始学习android 老师发了一份面试题 这个怎么做啊

SELECT * FROM Person WHERE P_ID not in (SELECT distinct(P_ID) FROM Order)

select * from persons p where not exists ( select 1 from orders o where p.pid = o.pid)

select (LastName||'_'||FirstName) from persons where P_ID not exsist(select P_ID from Orders)

select LastName,FirstName from persons p,order o where p.p_id(+)=o.p_id and orderno is null;

select LastName||'_'||FirstName from Persons p left join Orders o on p.P_ID = o.P_ID where o.O_ID is null