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?

Best,

David

Responses

• Re: array_agg() NULL Handling at 2010-09-01 06:56:58 from Thom Brown
• Re: array_agg() NULL Handling at 2010-09-01 07:30:08 from Pavel Stehule

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