TRIM_ARRAY Function

trim_array

SinceVersion dev

Description

Removes <size> elements from the end of <arr> while preserving the order of the remaining elements.

Syntax

TRIM_ARRAY(<arr>, <size>)

Parameters

Parameter	Description
<arr>	The input ARRAY<T>. T can be a numeric, boolean, string, date/time, IP, or complex type.
<size>	A non-negative BIGINT specifying how many elements to remove from the end. It cannot exceed the cardinality of <arr>.

Return Value

Returns an ARRAY<T> containing the first cardinality(<arr>) - <size> elements of <arr>.

• If <size> is 0, returns the input array unchanged.
• If <size> equals the array cardinality, returns an empty array.
• If either argument is NULL, returns NULL.
• NULL elements inside the array are preserved.
• If <size> is negative or exceeds the array cardinality, returns an error.

Examples

Remove two elements from the end:

SELECT trim_array([1, 2, 3, 4], 2);

[1, 2]

A size of zero leaves the array unchanged:

SELECT trim_array(['a', 'b', 'c'], 0);

["a", "b", "c"]

Remove all elements:

SELECT trim_array([1, 2, 3], 3);

[]

NULL elements and nested arrays are supported:

SELECT trim_array([[1, NULL], [2, 3], [4, 5]], 1);

[[1, null], [2, 3]]

A NULL argument produces NULL:

SELECT trim_array(CAST(NULL AS ARRAY<INT>), 0);

NULL

A size larger than the array cardinality produces an error:

SELECT trim_array([1, 2, 3], 4);

ERROR 1105 (HY000): size must not exceed array cardinality 3: 4

Keywords

ARRAY, TRIM, TRIM_ARRAY