Possible Bug

On 2011-02-09 10.51, Kaloyan Iliev Iliev wrote:

Hi,
I think I found something strange in PostgreSQL behavior. Here is an
example:

testdb=# CREATE TABLE test1 (test2 text, test3 text);
CREATE TABLE
testdb=# SELECT A.name FROM test1 A;
name
------
(0 rows)

testdb=# INSERT INTO test1 (test2,test3) VALUES ('1','2');
INSERT 0 1
testdb=# INSERT INTO test1 (test2,test3) VALUES ('3','4');
INSERT 0 1
testdb=# SELECT A.name FROM test1 A;
name -------
(1,2)
(3,4)
(2 rows)

customer.20080408=# SELECT name FROM test1;
ERROR: column "name" does not exist
LINE 1: SELECT name FROM test1;

testdb=# SELECT version();
version
----------------------------------------------------------------------------------------------------------

PostgreSQL 8.4.5 on amd64-portbld-freebsd8.1, compiled by GCC cc (GCC)
4.2.1 20070719 [FreeBSD], 64-bit
(1 row)

Obviously there is no column with name "name", but the SELECT query
(ONLY WHEN I USE ALIASES) returns result for it.
And if I have a column with name "name_en" and by mistake write it
"name", instead of error I receive strange data (ARRAY from all
columns), that I don't expect.

Could you tell me if this is a bug or some feature I haven't heard of.

Look up functional notation in
http://www.postgresql.org/docs/9.0/static/xfunc-sql.html#AEN46042

These are the same thing:
select name(test1) from test1;
select test.name from test1;

Best regards,
Kaloyan Iliev

--
Regards,
Robert "roppert" Gravsjö

On Wednesday, February 09, 2011 1:51:38 am Kaloyan Iliev Iliev wrote:

Hi,
I think I found something strange in PostgreSQL behavior. Here is an
example:

testdb=# CREATE TABLE test1 (test2 text, test3 text);
CREATE TABLE
testdb=# SELECT A.name FROM test1 A;
name
------
(0 rows)

testdb=# INSERT INTO test1 (test2,test3) VALUES ('1','2');
INSERT 0 1
testdb=# INSERT INTO test1 (test2,test3) VALUES ('3','4');
INSERT 0 1
testdb=# SELECT A.name FROM test1 A;
name
-------
(1,2)
(3,4)
(2 rows)

customer.20080408=# SELECT name FROM test1;
ERROR: column "name" does not exist
LINE 1: SELECT name FROM test1;

testdb=# SELECT version();

version
---------------------------------------------------------------------------
------------------------------- PostgreSQL 8.4.5 on
amd64-portbld-freebsd8.1, compiled by GCC cc (GCC) 4.2.1 20070719
[FreeBSD], 64-bit
(1 row)

Obviously there is no column with name "name", but the SELECT query
(ONLY WHEN I USE ALIASES) returns result for it.
And if I have a column with name "name_en" and by mistake write it
"name", instead of error I receive strange data (ARRAY from all
columns), that I don't expect.

Could you tell me if this is a bug or some feature I haven't heard of.

Depending on your point of view both. For a good explanation see:

http://www.depesz.com/index.php/2010/11/08/waiting-for-9-1-removed-autocast-
footgun/

As detailed above this feature will go away in 9.1.

Best regards,
Kaloyan Iliev

--
Adrian Klaver
adrian.klaver@gmail.com