ARRAY_CONCAT

​

Syntax

​

Scalar

array_concat(array, ...)

​

Arguments

• T is the array element type: BOOLEAN, TINYINT, SMALLINT, INTEGER, BIGINT, FLOAT, DOUBLE, DECIMAL(p, s), STRING, BINARY, DATE, TIME, TIMESTAMP, ARRAY, MAP or STRUCT.

​

Returns

• Type: ARRAY<T>
• Possible values: All elements of the non-NULL input arrays.
• NULL behavior: Skips NULL arrays; returns NULL only when every input array is NULL. NULL elements inside arrays are retained.
• Shape: The sum of non-NULL input lengths.
• Ordering: Argument order, retaining order within each array.

​

Properties

​

Usage notes

• Compatible element types are promoted to a common result type.
• Supply one or more arrays. Nested dimensions and compatible element types are combined as needed. Incompatible element types raise an error.
• INTEGER and INT mean the same type; STRING means VARCHAR text. NULL can be used with a supported type. Cast NULL explicitly when its type would otherwise be unclear.

​

Examples

​

Typical behavior

SELECT array_concat(ARRAY[1, 2], ARRAY[3, NULL]) AS "value";

​

Join arrays of strings

SELECT array_concat(ARRAY('red'), ARRAY('blue', 'green')) AS colors;