Categories:

Semi-structured and Structured Data Functions (Array/Object)

ARRAYS_TO_OBJECT¶

Returns an OBJECT that contains the keys specified by one input ARRAY and the values specified by another input ARRAY.

Syntax¶

ARRAYS_TO_OBJECT( <key_array> , <value_array> )
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Arguments¶

key_array

ARRAY of VARCHAR values that specify the keys for the new OBJECT.

value_array

ARRAY of values for the new OBJECT. This ARRAY must be the same length as key_array. The values in this ARRAY should correspond to the keys in key_array.

Returns¶

The function returns a value of the type OBJECT. The OBJECT contains the keys and values specified by the input ARRAYs.

Usage Notes¶

  • If any element in key_array is not a string, the function reports the following error:

    215002 (22000): Key supplied for ARRAYS_TO_OBJECT does not have string type
    
  • key_array and value_array must be equal in length. Otherwise, the function reports the following error:

    215001 (22000): Key array and value array had unequal lengths in ARRAYS_TO_OBJECT
    
  • If an element in key_array is NULL, that key and the corresponding value are omitted from the returned OBJECT.

    If the key is not NULL but the corresponding element in value_array is NULL, the key and NULL value are included in the returned OBJECT.

  • The returned OBJECT does not necessarily preserve the original order of the key-value pairs.

Examples¶

The following example returns an OBJECT that contains key-value pairs specified by two input ARRAYs:

SELECT ARRAYS_TO_OBJECT(['key1', 'key2', 'key3'], [1, 2, 3]);
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+-------------------------------------------------------+
| ARRAYS_TO_OBJECT(['KEY1', 'KEY2', 'KEY3'], [1, 2, 3]) |
|-------------------------------------------------------|
| {                                                     |
|   "key1": 1,                                          |
|   "key2": 2,                                          |
|   "key3": 3                                           |
| }                                                     |
+-------------------------------------------------------+

In the following example, the ARRAY of keys includes a NULL value. That key and the corresponding value are omitted from the returned OBJECT.

SELECT ARRAYS_TO_OBJECT(['key1', NULL, 'key3'], [1, 2, 3]);
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+-----------------------------------------------------+
| ARRAYS_TO_OBJECT(['KEY1', NULL, 'KEY3'], [1, 2, 3]) |
|-----------------------------------------------------|
| {                                                   |
|   "key1": 1,                                        |
|   "key3": 3                                         |
| }                                                   |
+-----------------------------------------------------+

In the following example, the ARRAY of values includes a NULL value. That value and the corresponding key are included in the returned OBJECT.

SELECT ARRAYS_TO_OBJECT(['key1', 'key2', 'key3'], [1, NULL, 3]);
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+----------------------------------------------------------+
| ARRAYS_TO_OBJECT(['KEY1', 'KEY2', 'KEY3'], [1, NULL, 3]) |
|----------------------------------------------------------|
| {                                                        |
|   "key1": 1,                                             |
|   "key2": null,                                          |
|   "key3": 3                                              |
| }                                                        |
+----------------------------------------------------------+