mariadb/mysql-test/r/func_isnull.result

drop table if exists t1;
create table t1 (id int auto_increment primary key not null, mydate date not null);
insert into t1 values (0,"2002-05-01"),(0,"2002-05-01"),(0,"2002-05-01");
flush tables;
select * from t1 where isnull(to_days(mydate));
id	mydate
drop table t1;