JSON_MAP_TRANSFORM_KEYS (Lakehouse v1)

Applies a transformation to each key in a JSON object using a lambda expression.

SQL Syntax

JSON_MAP_TRANSFORM_KEYS(<json_object>, (<key>, <value>) -> <key_transformation>)

Return Type

Returns a JSON object with the same values as the input JSON object, but with keys modified according to the specified lambda transformation.

SQL Examples

This example appends “_v1” to each key, creating a new JSON object with modified keys:

SELECT JSON_MAP_TRANSFORM_KEYS('{"name":"John", "role":"admin"}'::VARIANT, (k, v) -> CONCAT(k, '_v1')) AS versioned_metadata;

┌──────────────────────────────────────┐
│          versioned_metadata          │
├──────────────────────────────────────┤
│ {"name_v1":"John","role_v1":"admin"} │
└──────────────────────────────────────┘