1.	select e1.name, e2.name
from employee e1, employee e2
where e1.salary < (select e3.salary
from employee e3
where e2.id = e3.id)
order by e1.id asc, e1.salary desc;

2.      select name
from employee
group by name, phone, age
having count(*) > 1;


3. 	select
	e.name,
	u.uin
from
	employee e,
	employee_uin u
where
	e.id = u.id(+);

4.	an exception is raise

5.	1,2,3

6.	select
	nvl(c.customer_name,'N/A'),
	nvl(p.product_name,'N/A'),
	nvl(ii.quantity,0)
from
	customer c full outer join invoice i
on
	i.customer_id = c.id
full outer join invoice_item ii
on ii.invoice_id = i.id
full outer join product p
on ii.product_id = p.id
order by
	c.id, p.id, ii.id;


7.	Select
    'customer '||c.id||' '||c.customer_name
from
    customer c FULL outer join invoice i
on
    i.customer_id = c.id
where     i.invoice_number is null
union
select
    'product '||p.id||' '||p.product_name
from
    invoice_item ii full outer join product p
on ii.product_id = p.id
where ii.invoice_id is null;

8.	DBA

9.	Nested Anonymous block

10.	False

11.	subprogram must be compiled in the debug mode

12.	True

13.	it give the error location only for the top level subprogram call

14.	Smart data tab

15.     first statement

16.	10

17.	it is faster to execute than static sql

18.	the condition will evaluate to false

19.     where others handler