T-SQL: How do I get the rows from one table whose values completely match up with values in another table?

Question

Given the following:

declare @a table
(
    pkid int,
    value int
)

declare @b table
(
    otherID int,
    value int
)


insert into @a values (1, 1000)
insert into @a values (1, 1001)
insert into @a values (2, 1000)
insert into @a values (2, 1001)
insert into @a values (2, 1002)

insert into @b values (-1, 1000)
insert into @b values (-1, 1001)
insert into @b values (-1, 1002)

How do I query for all the values in @a that completely match up with @b?

{@a.pkid = 1, @b.otherID = -1} would not be returned (only 2 of 3 values match)

{@a.pkid = 2, @b.otherID = -1} would be returned (3 of 3 values match)

Refactoring tables can be an option.

EDIT: I've had success with the answers from James and Tom H.

When I add another case in @b, they fall a little short.

insert into @b values (-2, 1000)

Assuming this should return two additional rows ({@a.pkid = 1, @b.otherID = -2} and {@a.pkid = 2, @b.otherID = -2}, it doesn't work. However, for my project this is not an issue.

Answer 1

This is more efficient (it uses TOP 1 instead of COUNT), and works with (-2, 1000):

SELECT  *
FROM    (
        SELECT  ab.pkid, ab.otherID,
                (
                SELECT  TOP 1 COALESCE(ai.value, bi.value)
                FROM    (
                        SELECT  *
                        FROM    @a aii
                        WHERE   aii.pkid = ab.pkid
                        ) ai
                FULL OUTER JOIN
                        (
                        SELECT  *
                        FROM    @b bii
                        WHERE   bii.otherID = ab.otherID
                        ) bi
                ON      ai.value = bi.value
                WHERE   ai.pkid IS NULL OR bi.otherID IS NULL
                ) unmatch
        FROM
                (
                SELECT  DISTINCT pkid, otherid
                FROM    @a a , @b b
                ) ab
        ) q
WHERE   unmatch IS NOT NULL