AWS IoT SQL: What happens if I SELECT a JSON payload key that doesn't exist?

Hi,

Let's assume I have the following AWS IoT SQL statement:

SELECT device, room, value FROM 'topic/subtopic'

and this runs over the following incoming payload:

{
"device": "sensor1",
"value": 34
}

Will the resulting output from this SQL statement be:

{
"device": "sensor1",
"room": "",
"value": 34
}

or

{
"device": "sensor1",
"room": "null",
"value": 34
}

or:

{
"device": "sensor1",
"value": 34
}

or something else entirely? Or would the rule raise a parsing error or the like?