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POSTGRESQL BUG REPORT TEMPLATE
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Your name : Jochen Scharrlach
Your email address : Jochen.Scharrlach@schwaben.de
Category : runtime: back-end: SQL
Severity : non-critical
Summary: sum() + "group by" with an empty result returns one complete empty row
System Configuration
--------------------
Operating System : Linux RedHat 5.2
PostgreSQL version : 6.5
Compiler used : gcc 2.7.3
Hardware:
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Linux cepheus 2.2.7 #12 Mit Mai 12 18:21:15 CEST 1999 i686 unknown
96MB RAM, PPro 200MHz
Versions of other tools:
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Problem Description:
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My Java-app uses some group-by statements which are expected
to return empty resultsets if the result *is* empty - and it
doesn't like getting one row consisting of null-values...
It works fine with Oracle and it seems to be reasonable the
way Oracle handles it, so I *think* it's a bug :)
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Test Case:
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psql output of a simple example:
----snip----
js=> create table testi (number int, name varchar(40));
CREATE
js=> insert into testi values (1, 'myname');
INSERT 151274 1
js=> select sum(number) from testi where name='myname';
sum
---
1
(1 row)
js=> select * from testi where name='notthere';
number|name
------+----
(0 rows)
js=> select sum(number) , name from testi where name='notthere' group by
name;
sum|name
---+----
|
(1 row)
----snip----
This crashes my little app (because of the empty row) which works fine
with Oracle:
----snip----
SQL> create table testi (n int, name varchar(40));
Table created.
SQL> insert into testi values (1, 'myname');
1 row created.
SQL> select sum(n) from testi where name='myname';
SUM(N)
----------
1
SQL> select * from testi where name='notthere';
no rows selected
SQL> select sum(n), name from testi where name='notthere' group by name;
no rows selected
----snip----
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Solution:
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