ARRAY_COMPACT

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Syntax

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Scalar

array_compact(array)

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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.

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Returns

• Type: ARRAY<T>
• Possible values: The retained elements, including duplicates.
• NULL behavior: Returns NULL for a NULL array. NULL elements are removed.
• Shape: Zero through the original number of elements.
• Ordering: Original encounter order.

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Properties

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Usage notes

• 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.

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Examples

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Typical behavior

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

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Keep non-NULL strings

SELECT array_compact(ARRAY('red', CAST(NULL AS VARCHAR), 'blue')) AS colors;