Since SQLite version 3.20.0 (2017-08-01), date/time functions have been
allowed in contexts that require deterministic functions as long as they
did not make use of 'now', 'localtime', or 'utc' keywords since it was
assumed that the date-time functions would be deterministic without those
keywords. However, as
forum thread 28ab8d7150?t=h
demonstrates, a date/time function with no arguments can also be
non-deterministic. This results in illegal schemas like:
CREATE TABLE t1(a, b AS (datetime()));
CREATE TABLE t2(x CHECK( x<julianday() ));