21.4. Retrieving JSON Keys (json_keys) #
Required privileges: Postgres Pro AXE administrator only. For a full list of stored procedures and privileges, refer to Section 12.1.
Execute the following command on the Postgres Pro AXE server:
SELECT json_keys(JSON[,path]) ON CONFLICT DO NOTHING;
Where:
JSON: The JSON data from which keys must be retrieved.You must specify a JSON string literal or a column with JSON data.
path: The path to the JSON element from which keys must be retrieved.You can use JSONPath (e.g.,
$.family) or JSON Pointer (e.g.,/family). A list of paths can also be specified, in which case a list of keys for each path is returned.Optional parameter.
Postgres Pro AXE returns the keys of the JSON data.
Example 21.4. Executing the json_keys Stored Procedure
JSON data in the j column of the example table:
{
"family": "anatidae",
"species": ["duck", "goose", "swan", null]
}
Retrieving JSON keys:
SELECT json_keys(j) FROM example;
[family, species]