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map_from_arrays

Description​

Creates a MAP value from the given pair of key item array and value item array.

This function is supported from v3.1 onwards.

Syntax​

MAP map_from_arrays(ARRAY keys, ARRAY values)

Parameters​

  • keys: uses to construct the keys of the result MAP. Make sure the elements of keys are unique.
  • values: used to construct the values of the result MAP.

Return value​

Returns a MAP that is constructed from the input keys and values.

  • Keys and values must have the same length, otherwise it will return an error.
  • If key or value is NULL, this function returns NULL.
  • The returned MAP value has distinct keys.

Examples​

select map_from_arrays([1, 2], ['Star', 'Rocks']);
+--------------------------------------------+
| map_from_arrays([1, 2], ['Star', 'Rocks']) |
+--------------------------------------------+
| {1:"Star",2:"Rocks"}                       |
+--------------------------------------------+
select map_from_arrays([1, 2], NULL);
+-------------------------------+
| map_from_arrays([1, 2], NULL) |
+-------------------------------+
| NULL                          |
+-------------------------------+

select map_from_arrays([1,3,null,2,null],['ab','cdd',null,null,'abc']);
+--------------------------------------------------------------------------+
| map_from_arrays([1, 3, NULL, 2, NULL], ['ab', 'cdd', NULL, NULL, 'abc']) |
+--------------------------------------------------------------------------+
| {1:"ab",3:"cdd",2:null,null:"abc"}                                       |
+--------------------------------------------------------------------------+