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Re: array_agg() NULL Handling
On 1 September 2010 07:56, Thom Brown <thom(at)linux(dot)com> wrote: > On 1 September 2010 06:45, David E. Wheeler <david(at)kineticode(dot)com> wrote: >> The aggregate docs say: >> >>> The first form of aggregate expression invokes the aggregate across all input rows for which the given expression(s) yield non-null values. (Actually, it is up to the aggregate function whether to ignore null values or not — but all the standard ones do.) >> >> -- http://developer.postgresql.org/pgdocs/postgres/sql-expressions.html#SYNTAX-AGGREGATES >> >> That, however, is not true of array_agg(): >> >> try=# CREATE TABLE foo(id int); >> CREATE TABLE >> try=# INSERT INTO foo values(1), (2), (NULL), (3); >> INSERT 0 4 >> try=# select array_agg(id) from foo; >> array_agg >> ────────────── >> {1,2,NULL,3} >> (1 row) >> >> So are the docs right, or is array_agg() right? > > I think it might be both. array_agg doesn't return NULL, it returns > an array which contains NULL. The second I wrote that, I realised it was b*ll%$ks, as I was still in the process of waking up. -- Thom Brown Twitter: @darkixion IRC (freenode): dark_ixion Registered Linux user: #516935
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- Re: array_agg() NULL Handling at 2010-09-01 06:56:58 from Thom Brown
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- Re: array_agg() NULL Handling at 2010-09-01 16:02:12 from David E. Wheeler
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