"James B. Byrne" <byrnejb@harte-lyne.ca> writes:
> Given a datetime column, not null, is there a single syntax that
> permits searching for all dates in a given year, year+month, and
> year+month+day such that a single parameterised query can handle all
> three circumstances?
Try date_trunc() ... however, if you want the query to be indexable,
it'll take a bit more work.
regards, tom lane