The correct query would be "select f.c1, f.c2 from foo f;" if you want to use alias....
Patrick
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Patrick Fiche
email : patrick.fiche@aqsacom.com
tél : 01 69 29 36 18
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Hello,
I think I have found a query problem when the query has an alias for a table and use alias item and table name.
I ilustrate the problem with a simple table and query.
prr=# create table foo (c1 int2, c2 int2);
CREATE TABLE
prr=# insert into foo values (1, 1);
INSERT 301891 1
prr=# insert into foo values (2, 2);
INSERT 301892 1
prr=# select * from foo;
c1 | c2
----+----
1 | 1
2 | 2
(2 filas)
prr=# select foo.c1, f.c2 from foo f; -- >>> Incorrect result <<<
c1 | c2
----+----
1 | 1
2 | 1
1 | 2
2 | 2
(4 filas)
prr=# explain select foo.c1, f.c2 from foo f; -- >>> Incorrect query plan <<<
QUERY PLAN
-------------------------------------------------------------------
Nested Loop (cost=20.00..20040.00 rows=1000000 width=4)
-> Seq Scan on foo f (cost=0.00..20.00 rows=1000 width=2)
-> Materialize (cost=20.00..30.00 rows=1000 width=2)
-> Seq Scan on foo (cost=0.00..20.00 rows=1000 width=2)
(4 filas)
The result of the "select foo.c1, f.c2 from foo f" isn't correct, it do a cartesian product of foo table.
My version of PostgreSQL is PostgreSQL 7.4.5 on i386-pc-linux-gnu, compiled by GCC i386-linux-gcc (GCC) 3.3.4 (Debian 1:3.3.4-9).
Is this a bug?, is fixed in posteriors versions?
Thanks in advance,
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