PostgreSQL 18 reference · Array Functions

PostgreSQL ARRAY_CAT() Function

Concatenate two arrays of the same element type into one new array. The || operator does the same thing.

PostgreSQL 18

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Syntax

array_cat(array1, array2)

Parameter	Description
`array1, array2`	Arrays of the same element type.

A new array.

Join arrays

SELECT array_cat(ARRAY[1, 2], ARRAY[3, 4]) AS joined;

Output

  joined
-----------
 {1,2,3,4}
(1 row)

Run this on your computer — see “Get Started” for setup.

Two-dimensional arrays

SELECT array_cat(ARRAY[[1, 2]], ARRAY[[3, 4]]) AS two_rows;

Output

   two_rows
---------------
 {{1,2},{3,4}}
(1 row)

Run this on your computer — see “Get Started” for setup.

ARRAY_APPEND() · Add an element to the end of an array. array_prepend() adds to the start, and || joins arrays or elements.
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