Converts each array element to its text representation, and concatenates those using an optional delimiter. If no delimiter is provided, an empty string is used instead. NULL array elements are omitted.

Alias: ARRAY_JOIN

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Syntax

ARRAY_TO_STRING(<array>[, <delimiter>])

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Parameters

ParameterDescriptionSupported input types
<array>An array to be concatenatedARRAY
<delimiter>The delimiter used for concatenating the array elementsTEXT

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Return Type

TEXT

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Example

In the example below, the three elements are concatenated with no delimiter.

SELECT
	ARRAY_TO_STRING([ '1', '2', '3' ]) AS levels;

Returns: 123

In this example below, the levels are concatenated separated by a comma.

SELECT
	ARRAY_TO_STRING([ '1', '2', '3' ], ',') AS levels;

Returns: 1,2,3

In this example below, the elements of a nested array containing a NULL are concatenated.

SELECT
	ARRAY_TO_STRING([ [ 1, 2 ], [3, 4], [NULL, 5] ], ',') AS levels;

Returns: 1,2,3,4,5