Map functions - Amazon OpenSearch Service

Map functions

Note

To see which AWS data source integrations support this SQL command, see Supported OpenSearch SQL commands and functions.

Function Description
element_at(array, index) Returns element of array at given (1-based) index.
element_at(map, key) Returns value for given key. The function returns NULL if the key is not contained in the map.
map(key0, value0, key1, value1, ...) Creates a map with the given key/value pairs.
map_concat(map, ...) Returns the union of all the given maps
map_contains_key(map, key) Returns true if the map contains the key.
map_entries(map) Returns an unordered array of all entries in the given map.
map_from_arrays(keys, values) Creates a map with a pair of the given key/value arrays. All elements in keys should not be null
map_from_entries(arrayOfEntries) Returns a map created from the given array of entries.
map_keys(map) Returns an unordered array containing the keys of the map.
map_values(map) Returns an unordered array containing the values of the map.
str_to_map(text[, pairDelim[, keyValueDelim]]) Creates a map after splitting the text into key/value pairs using delimiters. Default delimiters are ',' for `pairDelim` and ':' for `keyValueDelim`. Both `pairDelim` and `keyValueDelim` are treated as regular expressions.
try_element_at(array, index) Returns element of array at given (1-based) index. If Index is 0, the system will throw an error. If index < 0, accesses elements from the last to the first. The function always returns NULL if the index exceeds the length of the array.
try_element_at(map, key) Returns value for given key. The function always returns NULL if the key is not contained in the map.

Examples

-- element_at
SELECT element_at(array(1, 2, 3), 2);
+-----------------------------+
|element_at(array(1, 2, 3), 2)|
+-----------------------------+
|                            2|
+-----------------------------+
SELECT element_at(map(1, 'a', 2, 'b'), 2);
+------------------------------+
|element_at(map(1, a, 2, b), 2)|
+------------------------------+
|                             b|
+------------------------------+
-- map
SELECT map(1.0, '2', 3.0, '4');
+--------------------+
| map(1.0, 2, 3.0, 4)|
+--------------------+
|{1.0 -> 2, 3.0 -> 4}|
+--------------------+
-- map_concat
SELECT map_concat(map(1, 'a', 2, 'b'), map(3, 'c'));
+--------------------------------------+
|map_concat(map(1, a, 2, b), map(3, c))|
+--------------------------------------+
|                  {1 -> a, 2 -> b, ...|
+--------------------------------------+
-- map_contains_key
SELECT map_contains_key(map(1, 'a', 2, 'b'), 1);
+------------------------------------+
|map_contains_key(map(1, a, 2, b), 1)|
+------------------------------------+
|                                true|
+------------------------------------+
SELECT map_contains_key(map(1, 'a', 2, 'b'), 3);
+------------------------------------+
|map_contains_key(map(1, a, 2, b), 3)|
+------------------------------------+
|                               false|
+------------------------------------+
-- map_entries
SELECT map_entries(map(1, 'a', 2, 'b'));
+----------------------------+
|map_entries(map(1, a, 2, b))|
+----------------------------+
|            [{1, a}, {2, b}]|
+----------------------------+
-- map_from_arrays
SELECT map_from_arrays(array(1.0, 3.0), array('2', '4'));
+---------------------------------------------+
|map_from_arrays(array(1.0, 3.0), array(2, 4))|
+---------------------------------------------+
|                         {1.0 -> 2, 3.0 -> 4}|
+---------------------------------------------+
-- map_from_entries
SELECT map_from_entries(array(struct(1, 'a'), struct(2, 'b')));
+---------------------------------------------------+
|map_from_entries(array(struct(1, a), struct(2, b)))|
+---------------------------------------------------+
|                                   {1 -> a, 2 -> b}|
+---------------------------------------------------+
-- map_keys
SELECT map_keys(map(1, 'a', 2, 'b'));
+-------------------------+
|map_keys(map(1, a, 2, b))|
+-------------------------+
|                   [1, 2]|
+-------------------------+
-- map_values
SELECT map_values(map(1, 'a', 2, 'b'));
+---------------------------+
|map_values(map(1, a, 2, b))|
+---------------------------+
|                     [a, b]|
+---------------------------+
-- str_to_map
SELECT str_to_map('a:1,b:2,c:3', ',', ':');
+-----------------------------+
|str_to_map(a:1,b:2,c:3, ,, :)|
+-----------------------------+
|         {a -> 1, b -> 2, ...|
+-----------------------------+
SELECT str_to_map('a');
+-------------------+
|str_to_map(a, ,, :)|
+-------------------+
|        {a -> NULL}|
+-------------------+
-- try_element_at
SELECT try_element_at(array(1, 2, 3), 2);
+---------------------------------+
|try_element_at(array(1, 2, 3), 2)|
+---------------------------------+
|                                2|
+---------------------------------+
SELECT try_element_at(map(1, 'a', 2, 'b'), 2);
+----------------------------------+
|try_element_at(map(1, a, 2, b), 2)|
+----------------------------------+
|                                 b|
+----------------------------------+