How do I *exclude* records based on the presence of a certain field (like the equivalent of SQL's `[fieldname] Is Null`)? **Example**: - Results for **Closed** questions include field **`closed_date=1234567890`**. - Results for **Open** questions do not include this field as a *`Null`* as I would expect. Is there a parameter I can add to the URL to **exclude questions that *have* the field**? ---------- The only information I could find was from the documentation: >**Absent Fields** > ><sub>To save space, the API does not return null values, instead opting to exclude the field altogether in the returned JSON. Fields that are not always guaranteed to be set (closed_date on question objects for example) are indicated in the per-type documentation. ([**Source**][1])</sub> [1]: https://api.stackexchange.com/docs/absent-fields