Syntax Arguments Return type Example See also

ARRAY_POSITIONS function

Returns an array of positions (indices) where the specified element appears in the input array. The indices are 0-based, where 0 indicates the first element, 1 indicates the second element, and so on. Returns an empty array if the element is not found.

Syntax


ARRAY_POSITIONS( array, value [, null_match] )

Arguments

array

A SUPER expression that specifies the array in which to search.

value

A value that specifies the element to search for.

null_match

A boolean value that specifies how NULL values are handled:

null_match = FALSE: Searching for NULL returns NULL. If the array contains NULL values and no match is found for a non-NULL search value, returns NULL.
null_match = TRUE: NULLs are treated as valid, searchable elements. If the array contains NULL values and no match is found for a non-NULL search value, it returns an empty array.

The default is TRUE.

Default NULL handling can also be specified by the configuration option:


-- same as null_match = TRUE
SET default_array_search_null_handling to TRUE;

Return type

The ARRAY_POSITIONS function returns a SUPER type.

Example

The following examples show the ARRAY_POSITIONS function.


SELECT ARRAY_POSITIONS(ARRAY('red', 'green', 'red'), 'red');
 array_positions 
-----------------
 [0,2]
(1 row)

SELECT ARRAY_POSITIONS(ARRAY(1, 2, 3), 4);
 array_positions 
-----------------
 []
(1 row)

The following examples show the function behavior with null_match set to TRUE.


SET default_array_search_null_handling to TRUE;

-- NULL search is enabled
SELECT ARRAY_POSITIONS(ARRAY('red', NULL, 'green', NULL), NULL);
 array_positions 
-----------------
 [1,3]
(1 row)

-- The array can contain NULLs
SELECT ARRAY_POSITIONS(ARRAY('red', NULL, 'green'), 'blue', TRUE);
 array_positions 
-----------------
 []
(1 row)

The following examples show the function behavior with null_match set to FALSE. Note that specifying the null_match behavior in the function will override the default configuration setting.


-- same as null_match = TRUE
SET default_array_search_null_handling to TRUE;

-- NULL search is disabled. The default behavior is overridden
SELECT ARRAY_POSITIONS(ARRAY('red', 'green'), NULL, FALSE);
 array_positions 
-----------------
 
(1 row)

-- same as null_match = FALSE
SET default_array_search_null_handling to FALSE;

-- The array contains NULL and a match is found
SELECT ARRAY_POSITIONS(ARRAY('red', NULL, 'green'), 'green');
 array_positions 
-----------------
 [2]
(1 row)

-- The array contains NULL but no match is found
SELECT ARRAY_POSITIONS(ARRAY('red', NULL, 'green'), 'blue');
 array_positions 
-----------------
 
(1 row)