SQLite 3 でミリ秒付きの日時を扱う例

sqlite3

select datetime('now', 'localtime');

create table R (
  id integer primary key not null, 
  created_at datetime); 

insert into R values( 1, '2020-06-25 19:30:30.001' ); 
insert into R values( 2, '2020-06-25 19:30:30.002' ); 
insert into R values( 3, '2020-06-25 19:30:30.003' ); 
insert into R values( 4, '2020-06-25 19:30:31.001' ); 

select * from R; 
select * from R where created_at < '2020-06-25 19:30:31.001'; 
select * from R where '2020-06-25 19:30:30.002' < created_at AND created_at < '2020-06-25 19:30:31.001'; 

select strftime("%s", created_at) + strftime("%f", created_at) - round( strftime("%f", created_at) ), created_at from R;

.exit