first post

Hi there, folks. This is my first post to this list, and I'm hoping I'm
posting to the right list from the Postgres page. I looked at several
different ones, and this seemed to be the one most suited to this
question.

I'm using Postgresql version 6.3.1, and I'm trying to execute the
following query:

select make, model, price, yr, mileage, extcol, intcol, image from
usedcars where (make='Ford' or make='Lincoln' ) and (model='Continental
Executive' );

First results:
make|model|price|yr|mileage|extcol|intcol|image
----+-----+-----+--+-------+------+------+-----
(0 rows)

Next query:
select make, model, price, yr, mileage, extcol, intcol, image from
usedcars where (make='Lincoln' or make='Ford') and (model='Continental
Executive') ;

Results:
make |model |price| yr|mileage|extcol|intcol
|image
-------+---------------------+-----+----+-------+------+------------+-----

Lincoln|Continental Executive|12000|1993| 69000|blue |blue leather|
(1 row)

I thought these two queries were logically identical, so I don't quite
understand the differing results. Finally, one more query. I repeat
the first query, and:

select make, model, price, yr, mileage, extcol, intcol, image from
usedcars where (make='Ford' or make='Lincoln') and (model='Continental
Executive') ;

make |model |price| yr|mileage|extcol|intcol
|image
-------+---------------------+-----+----+-------+------+------------+-----

Lincoln|Continental Executive|12000|1993| 69000|blue |blue leather|
(1 row)

Surprise!!! Would anybody be able to offer me a clue on this
behavior?? I'm pretty stumped.

TIA...

eric
--
***********************************************************
Eric McKeown ericm(at)palaver(dot)net
Palaver http://www.palaver.net
332 N. Market St. Phone: (219) 253-8131
Monon, IN 47959 Fax: (219) 253-6800
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