Is there a way to make Crystal Reports include a constant in a join condition, without using a SQL command object?

SELECT a.id, a.other, b.baz
FROM a
LEFT OUTER JOIN b
  ON a.id  = b.id
  AND b.bar = 'foo'

SELECT a.id, a.other, b.baz
FROM a
LEFT OUTER JOIN b
  ON a.id  = b.id
WHERE (b.bar IS NULL OR b.bar = 'foo')

SELECT a.id, a.other, b.baz
FROM a
LEFT OUTER JOIN b
  ON a.id  = b.id
WHERE (b.bar IS NULL OR b.bar = 'foo')

CREATE TABLE a (id INTEGER, other VARCHAR(32));
CREATE TABLE b (id INTEGER, bar VARCHAR(32), baz VARCHAR(32));
insert into A (id, other) values ('1', 'Has foo');
insert into A (id, other) values ('2', 'Has none');
insert into A (id, other) values ('3', 'Has foobar');
insert into B (id, bar, baz) values ('1', 'foo', 'Include');
insert into B (id, bar, baz) values ('1', 'foobar', 'Exclude');
insert into B (id, bar, baz) values ('1', 'another', 'Exclude');
insert into B (id, bar, baz) values ('1', 'More', 'Exclude');
insert into B (id, bar, baz) values ('3', 'foobar', 'Exclude');

CREATE TABLE a (id INTEGER, other VARCHAR(32));
CREATE TABLE b (id INTEGER, bar VARCHAR(32), baz VARCHAR(32));
insert into A (id, other) values ('1', 'Has foo');
insert into A (id, other) values ('2', 'Has none');
insert into A (id, other) values ('3', 'Has foobar');
insert into B (id, bar, baz) values ('1', 'foo', 'Include');
insert into B (id, bar, baz) values ('1', 'foobar', 'Exclude');
insert into B (id, bar, baz) values ('1', 'another', 'Exclude');
insert into B (id, bar, baz) values ('1', 'More', 'Exclude');
insert into B (id, bar, baz) values ('3', 'foobar', 'Exclude');

SELECT a.id, x.baz
FROM a
LEFT OUTER JOIN
 (SELECT id, baz FROM b WHERE bar = 'foo') As x ON a.id  = x.id

(Isnull({b.bar}) OR {b.bar} = "foo")