Join tables on nearest date in the past, in MySQL

Question

I have a sqlite query that I\'m trying to write. I have two tables:

TableA (sales): id sales date

TableB (goals): id goal date

I\'m selecting from Ta

Answer 1

Just get the cartesian product and then filter out uninteresting rows. Basically:

select a.*, b.*
from a, b
where
not exists (
  select null
  from b b2
  where abs(b2.date - a.date) < abs(b.date - a.date)
)

I don't know if SQLite supports that, tough.