Unnest multidimensional array

Library Snippets

Unnest a multidimensional array

Works with PostgreSQL

9.1+

Written in

SQL

Depends on

Nothing

Purpose: To emulate the unnest functionality for a multi-dimensional array. Courtesy of Pavel Stehule, from unnest on multi-dimensional arrays

NOTE: This will not work on an array of more than 2 dimensions. For an idea on how to handle multiple dimensions, take a look at Multidimensional Array Mapping

Function

CREATE OR REPLACE FUNCTION public.reduce_dim(anyarray) RETURNS SETOF anyarray AS $function$ DECLARE s $1%type; BEGIN FOREACH s SLICE 1 IN ARRAY $1 LOOP RETURN NEXT s; END LOOP; RETURN; END; $function$ LANGUAGE plpgsql IMMUTABLE; 

select reduce_dim(array[array[1, 2], array[2, 3], array[4,5], array[9,10]]); reduce_dim ------------ {1,2} {2,3} {4,5} {9,10}