There is a difference between: create table t0 (dt default (datetime()), event); and create table t1 (dt as (datetime()) stored, event); In the former case the value of dt is set once on row insert (if it is null or not provided by the insert statement) and can be updated at whim. In the latter case the value of dt is set when the row is inserted or updated but cannot be set by an insert or update statement. The only way to change these behaviours is though the use of triggers.