BOOLEAN data type?

Folks:

I had assumed that the BOOL column type was a tru boolean. That is, I
wrote some functions on the understand that, given table def:

CREATE TABLE order_details (
order_detail_id SERIAL NOT NULL PRIMARY KEY,
detail_id INT4 NOT NULL,
order_usq INT4 NOT NULL,
detail_required BOOL DEFAULT FALSE );

That the following query:

SELECT detail_id FROM order_detials
WHERE order_usq = 7703 AND detail_required;

... should be equivalent to:

SELECT detail_id FROM order_detials
WHERE order_usq = 7703 AND detail_required = TRUE;

However, in testing (7.1 RC2), the query turned out to mean this:

SELECT detail_id FROM order_detials
WHERE order_usq = 7703 AND detail_required IS NOT NULL;

... throwing off a lot of my results until I figured it out.

Can someone explain this to me? I thought the whole point of a BOOL
data type was that it could be treated as a Boolean value, and used for
testing and comparison without and "= TRUE" or "= FALSE". What's going
on here?

-Josh

______AGLIO DATABASE SOLUTIONS___________________________
Josh Berkus
Complete information technology josh(at)agliodbs(dot)com
and data management solutions (415) 565-7293
for law firms, small businesses fax 621-2533
and non-profit organizations. San Francisco