SurrealDB uses two types called None and Null to represent two different ways in which data may not exist.
Values can be specifically set to NONE in SurrealDB to remove a field from a record.
CREATE person SET children = NONE;
The NONE keyword can be written in anycase.
CREATE person SET children = NONE, siblings = none;
Values can be specifically set to NULL in SurrealDB to denote a field which is set, but which does not have a value.
CREATE person SET children = NULL;
The NULL keyword can be written in anycase.
CREATE person SET children = NULL, siblings = null;