Excerpts from John Gage's message of mar ago 03 16:21:58 -0400 2010:
> Grouping by summing numerical fields seems to be straightforward, but
> grouping by concatenating text fields escapes my search of the
> documentation.
You can create a new custom aggregate function that does this. It's
pretty straightforward. There are examples in the archives (search for
text_concat), but there's also a more modern way involving array_agg and
array_to_string.
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Álvaro Herrera <alvherre@commandprompt.com>
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