How to replace a complex SQL MINUS query with LEFT OUTER JOIN equivalent

Question

Trying to figure how how to replace the following, with equivalent left outer join:

select distinct(a.some_value)
from table_a a, table_b b
where a.id = b.a_         


        

Answer 1

Here's what my brain puts out after a beer:

select distinct
    a.some_value
from
    table_a a
    join table_b b on a.id = b.a_id
where
    b.some_id = 123
    and b.create_date < '2014-01-01' 
    and b.create_date >= '2013-12-01'  
    and not exists (
        select
            a2.some_value
        from
            table_a a2
            join table_b b2 on a2.id = b2.a_id
        where
            b2.some_id = 123
            and b2.create_date < '2013-12-01'
    )

Whether this'll optimize to faster than a left join or not is something I can't think of right now...