SQL & PL/SQL :: Pivot And Similar - Return Zip-codes That Exist?

I have an question.

- Imagine I have an table with several ZIPCODE.
- Imagine I want to return from that table the existence of several zipcodes I need to get.
- Imagine that I need to return both zipcodes that exists and both zipcodes that not exist.

The solution I've found to do this, was using the Pivot method, like the sample below, if there is another way to return anything like that. Return the zipcodes that exist, and the zipcodes that does not exist also!

Table Creation:

CREATE TABLE "AAA_ADDRESSZIPCODES"
("ZIPCODE" NUMBER,
"NAME" VARCHAR2(50 BYTE),
"COD_PLACE" NUMBER
)
Data:

Insert into GSCIS.AAA_ADDRESSZIPCODES (ZIPCODE,NAME,COD_PLACE) values (1100,'Portugal',2);
Insert into GSCIS.AAA_ADDRESSZIPCODES (ZIPCODE,NAME,COD_PLACE) values (1150,'Portugal',2);
Insert into GSCIS.AAA_ADDRESSZIPCODES (ZIPCODE,NAME,COD_PLACE) values (1000,'Portugal',1);
Insert into GSCIS.AAA_ADDRESSZIPCODES (ZIPCODE,NAME,COD_PLACE) values (1200,'Spain',2);

Select using Pivot:

SELECT *
FROM (SELECT distinct zipcode FROM aaa_addresszipcodes group by zipcode )
PIVOT ( count(zipcode) FOR zipcode IN (1000,1100,1200, 1150, 2000) )