Re: How to count the number of items in an Array?

Andre Lopes <lopes80andre@gmail.com> wrote:

> One more time, thanks for the reply. I'am using postgre 8.3. I think I don't
> have the array_agg(), there is another way of doing it?

Sure.

The doc contains an example for a user-defined aggregate-function:
http://www.postgresql.org/docs/8.4/interactive/xaggr.html

It works with versions prior 8.4.


test=*# CREATE AGGREGATE array_accum (anyelement)
test-# (
test(#     sfunc = array_append,
test(#     stype = anyarray,
test(#     initcond = '{}'
test(# );
CREATE AGGREGATE
Zeit: 44,645 ms
test=*# select array_accum(a) from foo;
 array_accum
-------------
 {1,3,5,7}
(1 Zeile)



Andreas
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