Query help for count

Question

Hi Experts,
I have a table like:
Id item1 item2
1 a b
2 x b
3 b a
4 x a
i need take count exact item1,item2 combination should be (a,b) or (b,a).
Is there any way to get the combinations counts.
Regs,
H

Answer 1

with xx as
(select 1 id,'a' item1,'b' item2 from dual union all
select 2 id,'x' item1,'b' item2 from dual union all
select 3 id,'b' item1,'a' item2 from dual union all
select 4 id,'x' item1,'a' item2 from dual union all
select 5 id,'x' item1,'b' item2 from dual union all
select 6 id,'a' item1,'b' item2 from dual union all
select 7 id,'b' item1,'a' item2 from dual
select count(*)  from xx
where (item1 = 'a' and item2 ='b') OR (item1 = 'b' and item2 ='a');