Construct an ARRAY value from a list of expressions.
ARRAY(expr1, expr2, ...)## Overview Constructs an ARRAY value from a list of expressions. ARRAY is the canonical literal constructor for array-typed values and is used everywhere a collection literal is needed: in DDL defaults, in projections that assemble per-row arrays from scalar columns, and in arguments to other array functions. Typical uses include building row-level arrays from individual column values, composing test fixtures inline, and constructing singleton arrays to pass to ARRAY_CAT or ARRAY_UNION. ## Behavior - Returns an ARRAY<T> whose element type T is the common super-type of the argument expressions. - Element order matches the order of the supplied expressions. - Zero-argument form requires an explicit type cast: CAST(ARRAY() AS ARRAY<INT>) produces an empty ARRAY<INT>. - NULL arguments are preserved as NULL elements; they do not cause the whole literal to become NULL. - The bracket syntax ARRAY[expr1, expr2, ...] is an equivalent form. - Never mutates its arguments. ## Null and empty handling - NULL expressions are accepted and appear as NULL elements. - An empty ARRAY() literal without a type cast raises because the element type is undefined. - The resulting array is non-NULL; even an all-NULL list produces a non-NULL array of NULLs. ## Compatibility - Matches the standard SQL array/map convention. Both function-call form and bracket form are accepted; behaviour is identical. - The element type is inferred from the widest common type; explicit casts may be required when mixing numeric widths.
| Name | Type | Description |
|---|---|---|
expr | Specifies one or more expressions that become the elements of the resulting array, in the order supplied. All expressions must share a compatible element type. |
-- Integer array
SELECT ARRAY(1, 2, 3); -- [1, 2, 3]-- String array
SELECT ARRAY('a', 'b', 'c'); -- ['a', 'b', 'c']-- Array with NULL elements
SELECT ARRAY(1, CAST(NULL AS INT), 3); -- [1, NULL, 3]-- Single-element array
SELECT ARRAY(42); -- [42]-- Bracket syntax is equivalent
SELECT ARRAY[10, 20, 30]; -- [10, 20, 30]-- Build a per-row constant array of tags derived from columns
SELECT session_id, ARRAY(country, device, browser) AS dimensions
FROM analytics.events.user_sessions;