Re: Merging rows into one result?

Jesper K. Pedersen <jkp(at)solnet(dot)homeip(dot)net> schrieb:

> Is it possible to use SQL to merge data into one result?
>
> A theorethical example to explain:
>
> tbl_test (
> id integer,
> information varchar(25))
>
> id | information
> ---+--------------
> 1 | Yo
> 2 | Go away
> 1 | Stay put
> 3 | Greetings
>
> Please note id is not unique and not a primary key.
>
> and I wonder if there is any functions to "merge" data (sort of
> concat'ing).
> A normal: select information from tbl_test where id=1
> would result in the rows
> Yo
> Stay put
>
> I would like a single row result in the format of:
> Yo Stay put

Yes, of corse, this is possible. You need a own aggregate-function. A
similar example for this task can you find here:

http://www.zigo.dhs.org/postgresql/#comma_aggregate

I think, it is very simple to rewrite this example for your purpose.

HTH, Andreas
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