How to Convert an Array to a String in BigQuery
Last updated July 26, 2026 · By the SaturnSQL team
ARRAY_TO_STRING(array, separator) joins an array's elements into one delimited string, the mirror image of SPLIT, which turns a string into an array.
SELECT order_id, ARRAY_TO_STRING(tags, ', ') AS tag_list
FROM orders;Handling NULL elements
ARRAY_TO_STRING errors if any element is NULL unless you pass a third argument to substitute for them.
SELECT ARRAY_TO_STRING(['a', NULL, 'b'], ', ', 'N/A') AS joined;
-- 'a, N/A, b'Arrays to rows vs arrays to strings
ARRAY_TO_STRING keeps one row per array, good for display. If you need one row per element instead, for filtering or joining, use UNNEST rather than this function.
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