DB2 show json_object as null if empty

Question

I want that the output of the select for the column FORMATTED_JSON is null if it is empty instead of empty object, means

IDENTIFIER | FORMATTED_JSON
1          | null 

This is the query:

SELECT IDENTIFIER, JSON_OBJECT('NAME' VALUE name, 'SIZE' VALUE SIZE FORMAT JSON ABSENT ON NULL) FORMATTED_JSON
FROM ABC

Answer 1

SELECT 
  IDENTIFIER
, NULLIF (JSON_OBJECT ('NAME' VALUE name, 'SIZE' VALUE SIZE ABSENT ON NULL), '{}') FORMATTED_JSON
FROM 
(
  VALUES 
    (1, 'N1', 'S1') 
  , (2, 'N2', NULL)
  , (3, NULL, NULL)
) ABC (IDENTIFIER, NAME, SIZE)

IDENTIFIER	FORMATTED_JSON
1	{"NAME":"N1","SIZE":"S1"}
2	{"NAME":"N2"}
3