Freebase MQL filter where value == null?

freebase, mql

Solution

You need to use "optional":"forbidden" directive:

[{
  "type": "/people/person",
  "date_of_birth": {
    "value":    null,
    "optional": "forbidden"
  },
  "name": null,
  "id":   null
}]​

(I added `"id":null` so that the Query Editor gives clickable links)

Note that query has a default `"limit":100,` if you want more results then add an explicit limit clause. If that times out, then you'll need to use a MQL cursor.

Problem

Can get all triples with value null in specific field? All people with date_of_birth equal null? ``` [ "type": "/people/person", "date_of_birth":null, "name":null ] ```

Original source