Re: Merging rows into one result?

Centuries ago, Nostradamus foresaw when jkp@solnet.homeip.net ("Jesper K. Pedersen") would write:
> 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
>
> Any ideas on this?

Sure, you could create a custom aggregate to append them using spaces.

Look in the PostgreSQL documentation under "CREATE AGGREGATE."  If you
check the online version at PostgreSQL.org, there are comments showing
examples...
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