SQL: relations, LEFT JOIN with spec column

[prog]

Hi all!

I apologize for may be stuped question and for my bad English too.

_INTRO_:

I have two tables:
product: id, title ...
accessory: id, title ...

and relation table "many to many":
product_accessory (pid, aid)

I know how to recieve the list of accessories that belongs to selected product (productId). SQL is:

"SELECT a.id, a.title
FROM product_accessory as rel LEFT JOIN accessory as a ON (a.id=rel.aid)
WHERE (rel.pid='sony_DCR-HC_20E')"

And the list of all accessories is, clear:
SELECT a.id, a.title FROM accessory AS a [WHERE filter_expression]

_QUESTION_:

But what that I want is to recieve for selected product the list of all(!) accessories, but with specialized column by which i can determine if the accessory belongs to selected product.

I tested some SQLs:

"SELECT a.id, a.title, rel.aid FROM accessory AS a
LEFT JOIN product_accessory AS rel ON rel.aid=a.id
WHERE (rel.pid='sony_DCR-HC_20E') or (rel.aid IS NULL)
ORDER BY a.title"

But there are not accessories in obtained list that present in the relation table except of selected product.

Or

"SELECT a.id, a.title, rel.pid='sony_DCR-HC_20E' FROM accessory AS a
LEFT product_accessory AS rel ON rel.aid=a.idORDER BY a.id"

But in this case there are unnecessary rows of dubble accessory - with difirenced third column.
(The same result is if DISTINCT in last SQL is used.)


I feel that the truth is nearby, but I have ranked my brains over this question all night long.

Thanks for help.
Alex Gudchenko.