Re: Concatenating string fields with GROUP BY clause
| От | Jason Hihn |
|---|---|
| Тема | Re: Concatenating string fields with GROUP BY clause |
| Дата | |
| Msg-id | NGBBLHANMLKMHPDGJGAPCENHCMAA.jhihn@paytimepayroll.com обсуждение исходный текст |
| Ответ на | Re: Concatenating string fields with GROUP BY clause ("Brian G. Huber" <brianghuber@yahoo.com>) |
| Список | pgsql-novice |
I was just working on a similar problem. I resulted in to doing it in code. HAVING would be the avenue, but it is just like a where clause and you can't say HAVING previous record's g field=this record's g field. :-( You must sort first by the g field then just spin through while the g fields are the same.
If anyone knows how to to it within SQL only, I'd appreciate knowing too.
-----Original Message-----
From: pgsql-novice-owner@postgresql.org [mailto:pgsql-novice-owner@postgresql.org]On Behalf Of Brian G. Huber
Sent: Tuesday, September 09, 2003 2:03 PM
To: Jeffrey Melloy
Cc: Godshall Michael; pgsql-novice@postgresql.org
Subject: Re: [NOVICE] Concatenating string fields with GROUP BY clauseThanks for the example Jeff - Well said - that is what I'm trying to do.----- Original Message -----From: Jeffrey MelloyTo: Brian G. HuberSent: Tuesday, September 09, 2003 12:52 PMSubject: Re: [NOVICE] Concatenating string fields with GROUP BY clauseI think what he's trying to do is this:
a | b | g
1 | sun | 1
2 | shoe | 1
3 | pea | 2
4 | door | 2
he gets this as the response:
group, sum, concat
1, 3, sunshoe
2, 7, peadoor
So a "concatenation aggregate"
That being said, I can't think of any simple way to do it in SQL.
Jeff
On Tuesday, September 9, 2003, at 12:29 PM, Brian G. Huber wrote:Thanks for the response - but II does not seem to work as an aggregate function - for example - if I use:
SELECT groupid, sum(numeric_field), ||(text_field) FROM table GROUP BY groupid
I get
ERROR: Unable to identify a prefix operator '||' for type 'text'
You may need to add parentheses or an explicit cast
Therefore, I think II concatenates two text columns, but does not aggregate. It would seem this is fairly common but there is no text aggregation function listed in 6.14 Aggregate Functions!!!
----- Original Message -----
From: Godshall Michael
To: 'Brian G. Huber' ; pgsql-novice@postgresql.org
Sent: Tuesday, September 09, 2003 12:10 PM
Subject: Re: [NOVICE] Concatenating string fields with GROUP BY clause
Concatenate is done with || in postgresql
-----Original Message-----
From: Brian G. Huber [mailto:brianghuber@yahoo.com]
Sent: Tuesday, September 09, 2003 12:02 PM
To: pgsql-novice@postgresql.org
Subject: [NOVICE] Concatenating string fields with GROUP BY clause
Hi -
I am trying to concatenate a text field in a query with a group by clause, similar to a sum() function on a numeric value - for example:
SELECT groupid, sum(numeric_field), ???(text_field) FROM table GROUP BY groupid
but I cannot find a function that will concatenate the text fields. Any comments appreciated!
TIA,BGH
В списке pgsql-novice по дате отправления: