At 03:10 PM 23/02/2007, you wrote:

>I want to write a following query
>
> select *
>
>from A
>
>where a.field1, a.field2
>
>in
>
>(select B.field1, B.field2
>
>from B)

You can't use IN() like that. It is for comparing one value with a
set of values.

Take care with table identifiers.

You can do this query as

select ax.* from A ax
where exists (
select 1 from B bx
where bx.field1 = ax.field1
and bx.field2 =ax.field2)

But an inner join may be less costly than the correlated existence query:

select
bx.field1,
bx.field2,
ax.aField,
ax......
from A ax join B bx
on bx.field1 = ax.field1
and bx.field2 = ax.field2

Tip: don't use select * at all. It was invented as a quick way for
lazy idiots to leave their signature in client applications.

./heLen