Hi,

My name is Ilir Gashi and I am Research Student at the Centre for Software
Reliability, City University, London. I found a (possible) bug in Firebird
1.0 (I know it is an old release but I do not have a newer one installed
and in any case I am only using the server for research purposes).

The script is as follows:

CREATE TABLE ta (c1 CHAR(1));
CREATE TABLE tb (c1 CHAR(1));
CREATE TABLE tc (c1 SMALLINT);

INSERT INTO ta VALUES('a');
INSERT INTO tb VALUES('b');
INSERT INTO tc VALUES(1);

SELECT c1 AS a,NULL AS b,NULL AS c FROM ta
UNION ALL
SELECT NULL,c1,NULL FROM tb
UNION ALL
SELECT NULL,NULL,c1 FROM tc;

SQL error code = -104
Invalid command
Data type unknown

The same query with the same tables in MS SQL Server 7 returns the results:

a b c
---- ---- ------
a NULL NULL
NULL b NULL
NULL NULL 1

(3 row(s) affected)

PostgreSQL 7.2 and Oracle 8.0.5 return the same (or similar) error message
to Firebird 1.0. So i have disagreements in the results retured by the
servers.

Is this a bug, or is this the intended behaviour in Firebird.

Looking forward to your reply.

Best regards,

Ilir

P.S. I am not sure whether this is the correct place to send this report.
If it is not then sorry for the inconvenience but can you give me a pointer
as to where I should report this.

p.p.s. This is the second time I am sending this message. Sorry if there
have been any duplicates but I did not see a copy of my first message
posted anywhere, so I was not sure whether it got through.
____________________________________________

Ilir Gashi
PhD Student
Centre for Software Reliability
City University
Northampton Square, London EC1V 0HB
email: i.gashi@...
website: http://www.csr.city.ac.uk/csr_city/staff/gashi/
____________________________________________