JSON_OBJECT_KEEP_NULL

Introduced or updated: v1.2.402

Creates a JSON object with keys and values.

• The arguments are zero or more key-value pairs(where keys are strings, and values are of any type).
• If a key is NULL, the key-value pair is omitted from the resulting object. However, if a value is NULL, the key-value pair will be kept.
• The keys must be distinct from each other, and their order in the resulting JSON might be different from the order you specify.
• TRY_JSON_OBJECT_KEEP_NULL returns a NULL value if an error occurs when building the object.

See also: JSON_OBJECT

Syntax

JSON_OBJECT_KEEP_NULL(key1, value1[, key2, value2[, ...]])

TRY_JSON_OBJECT_KEEP_NULL(key1, value1[, key2, value2[, ...]])

Return Type

JSON object.

Examples

SELECT JSON_OBJECT_KEEP_NULL();
┌─────────────────────────┐
│ json_object_keep_null() │
├─────────────────────────┤
│ {}                      │
└─────────────────────────┘

SELECT JSON_OBJECT_KEEP_NULL('a', 3.14, 'b', 'xx', 'c', NULL);
┌────────────────────────────────────────────────────────┐
│ json_object_keep_null('a', 3.14, 'b', 'xx', 'c', null) │
├────────────────────────────────────────────────────────┤
│ {"a":3.14,"b":"xx","c":null}                           │
└────────────────────────────────────────────────────────┘

SELECT JSON_OBJECT_KEEP_NULL('fruits', ['apple', 'banana', 'orange'], 'vegetables', ['carrot', 'celery']);
┌────────────────────────────────────────────────────────────────────────────────────────────────────┐
│ json_object_keep_null('fruits', ['apple', 'banana', 'orange'], 'vegetables', ['carrot', 'celery']) │
├────────────────────────────────────────────────────────────────────────────────────────────────────┤
│ {"fruits":["apple","banana","orange"],"vegetables":["carrot","celery"]}                            │
└────────────────────────────────────────────────────────────────────────────────────────────────────┘

SELECT JSON_OBJECT_KEEP_NULL('key');
  |
1 | SELECT JSON_OBJECT_KEEP_NULL('key')
  |        ^^^^^^^^^^^^^^^^^^ The number of keys and values must be equal while evaluating function `json_object_keep_null('key')`


SELECT TRY_JSON_OBJECT_KEEP_NULL('key');
┌──────────────────────────────────┐
│ try_json_object_keep_null('key') │
├──────────────────────────────────┤
│ NULL                             │
└──────────────────────────────────┘