using 'IN' in a query

Ok i have the following schema:
drop table x;
create table x
(

 a number, b number, c varchar(10), d blob,  CONSTRAINT pk_x PRIMARY KEY(a, b)
);

insert into x (a, b, c) values (5, 6, 'a');
insert into x (a, b, c) values (3, 2, 'b');
insert into x (a, b, c) values (3, 1, 'c');
insert into x (a, b, c) values (8, 7, 'd');

create or replace view v_x as select a, b, c, d from x order by a, b;

I want to do something like:
SELECT a, b,c,d FROM v_x WHERE a,b IN
(SELECT a,b FROM v_x WHERE rownum <= 3 MINUS SELECT a,b FROM v_x WHERE
rownum < 2);

But i get an error: "invalid relational operator"

I understand why the error occurs. But how do i do this type of query? I just want to get all rows where the Primary key matches the nested query. If the primary key is one column everything works fine (the IN operator works great with 1 column) but if the primary key is composite, i don't know how to form the query.

Note, i could have just executed the nested query by itself, i.e. SELECT a,b,c,d FROM v_x WHERE rownum <= 3 MINUS SELECT a,b,c,d FROM v_x WHERE rownum < 2
but MINUS does not work with BLOBS.

I hope this is clear.
thanx in advance
anthony Received on Tue Mar 12 2002 - 12:01:47 CST