select count(*) from call_log
where relation_id in (14,15)
and date(from_unixtime(created_time/1000)) = '2018-12-10';

结果：1600

select count(*) from call_log
where relation_id in (14,15)
and date(from_unixtime(created_time/1000)) = '2018-12-10'
and id not in (NULL);

结果：0

select count(*) from call_log
where relation_id in (14,15)
and date(from_unixtime(created_time/1000)) = '2018-12-10'
and id in (NULL);

结果：0
理想情况下，查询2和查询3的结果之和应该等于查询1的结果。或者与null比较时出现问题。