query problem in 7.2.1: serious planner issue
I cannot sort on a field that I join across tables. Here are the examples:
If I do this:
SELECT offers.lot_id, lots.project_id
FROM offers, lots
WHERE offers.lot_id = lots.lot_id
AND ...
UNION
SELECT offers.lot_id, lots_deleted.project_id
FROM offers, lots_deleted
WHERE offers.lot_id = lots_deleted.lot_id
AND ...
ORDER BY lot_id
Produces the error:
Error while executing the query; ERROR: ORDER BY 'lot_id' is ambiguous
And if I do this:
If I do this:
SELECT offers.lot_id, lots.project_id
FROM offers, lots
WHERE offers.lot_id = lots.lot_id
AND ...
UNION
SELECT offers.lot_id, lots_deleted.project_id
FROM offers, lots_deleted
WHERE offers.lot_id = lots_deleted.lot_id
AND ...
ORDER BY lots.lot_id
Produces the error:
Error while executing the query; ERROR: ORDER BY on a UNION/INTERSECT/EXCEPT
result must be on one of the result columns
Hmm, it does not like the table name reference either, so what if I rename
the result column...
If I try this:
SELECT offers.lot_id, lots.project_id, offer.lot_id AS offers_lot_id
FROM offers, lots
WHERE offers.lot_id = lots.lot_id
AND ...
UNION
SELECT offers.lot_id, lots_deleted.project_id, offer.lot_id AS offers_lot_id
FROM offers, lots_deleted
WHERE offers.lot_id = lots_deleted.lot_id
AND ...
ORDER BY offers_lot_id
Produces the error:
Error while executing the query; ERROR: ORDER BY on a UNION/INTERSECT/EXCEPT
result must be on one of the result columns
Just for fun I did ths:
SELECT offers.lot_id, lots.project_id
FROM offers, lots
WHERE offers.lot_id = lots.lot_id
AND ...
UNION
SELECT offers.lot_id, lots_deleted.project_id
FROM offers, lots_deleted
WHERE offers.lot_id = lots_deleted.lot_id
AND ...
ORDER BY offers_lot_id
Which of course does not work but produces the error:
Error while executing the query; ERROR: Attribute 'offer_lot_id' not found
Which distinguishes it from the previous error.
Is there a way to do what I am trying to do???
Terry Fielder
Network Engineer
Great Gulf Homes / Ashton Woods Homes
terry@greatgulfhomes.com
On Thu, 4 Jul 2002 terry@greatgulfhomes.com wrote:
I cannot sort on a field that I join across tables. Here are the examples:
If I do this:
SELECT offers.lot_id, lots.project_id
FROM offers, lots
WHERE offers.lot_id = lots.lot_id
AND ...
UNION
SELECT offers.lot_id, lots_deleted.project_id
FROM offers, lots_deleted
WHERE offers.lot_id = lots_deleted.lot_id
AND ...
ORDER BY lot_id
ORDER BY 1
Regards Herbie
--
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Herbert Liechti http://www.thinx.ch
The content management company. Visit http://www.contentx.ch
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
terry@greatgulfhomes.com writes:
I cannot sort on a field that I join across tables. Here are the examples:
If I do this:
ORDER BY lot_id
Produces the error:
Error while executing the query; ERROR: ORDER BY 'lot_id' is ambiguous
It does? I tried to duplicate this:
test72=# create table offers(lot_id int);
CREATE
test72=# create table lots(lot_id int, project_id int);
CREATE
test72=# create table lots_deleted(lot_id int, project_id int);
CREATE
test72=# SELECT offers.lot_id, lots.project_id FROM offers, lots
test72-# WHERE offers.lot_id = lots.lot_id
test72-# UNION
test72-# SELECT offers.lot_id, lots_deleted.project_id FROM offers, lots_deleted
test72-# WHERE offers.lot_id = lots_deleted.lot_id
test72-# ORDER BY lot_id;
lot_id | project_id
--------+------------
(0 rows)
Your third example (with AS) works fine too once I corrected the typos
(offer.lot_id -> offers.lot_id, etc).
In general, you can ORDER BY the column name or column number of
any output column of the UNION construct. If you want to use a
name then you'd better be sure only one output column has that name.
This is per SQL92 spec; we don't offer any extensions to sort on
non-output columns when we're dealing with a UNION.
regards, tom lane
On Thu, 4 Jul 2002 terry@greatgulfhomes.com wrote:
I cannot sort on a field that I join across tables. Here are the examples:
If I do this:
SELECT offers.lot_id, lots.project_id
FROM offers, lots
WHERE offers.lot_id = lots.lot_id
AND ...
UNION
SELECT offers.lot_id, lots_deleted.project_id
FROM offers, lots_deleted
WHERE offers.lot_id = lots_deleted.lot_id
AND ...
ORDER BY lot_id
ORDER BY 1
Where the number indicates the position of the column in the
resulting table
Regards Herbie
--
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Herbert Liechti http://www.thinx.ch
The content management company. Visit http://www.contentx.ch
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Import Notes
Resolved by subject fallback