Herouth Maoz wrote:
>
> At 14:08 +0300 on 25/08/1999, Giampiero Raschetti wrote:
>
> > ...............................
>
> I think you have a misunderstanding about the purpose of group by statements.
>
> In fact, the above seems to indicate that you are not well aware of what
> joins are, or at least you don't know that you have to restrict them to
> make sense of your data. You really have to add WHERE g.id = u.id.
>
OK. That's true. I'm not well aware of SQL in general but if you
try out that secuence into postgres 6.4.2 you will see that it works.
So I understand that probably it was not standard. Well.
Let's take a look at this same problem without any join involved
and if possible let me know how to obtain my target:
xaxa=> \d comuni
Table = comuni
+----------------------------------+----------------------------------+-------+
| Field | Type |
Length|
+----------------------------------+----------------------------------+-------+
| produtt | varchar()
| 40 |
| unital | varchar()
| 40 |
| comune | varchar()
| 40 |
| login | varchar()
| 8 |
+----------------------------------+----------------------------------+-------+
xaxa=> select * from comuni;
produtt| unital|comune |login
-------+---------------+------------+-----
xxx |199900200000100|POGGIRIDENTI|user1
yyy |199900200000100|POGGIRIDENTI|user2
yyy |199900200000100|ARDENNO |USER3
yyy |199900200000100|BORMIO |user2
(4 rows)
xaxa=> select * from comuni group by login;
ERROR: Illegal use of aggregates or non-group column in target list
xaxa=>
This works too on Postgres 6.4.2 so how can I obtain a list of
unique users from this table on 6.5.1 ?
Many Thanks
--
Best Regards
----------------------------
Giampiero Raschetti
Sistemi Innovativi
Banca Popolare di Sondrio
----------------------------
