MySQL NOT IN查询给出错误结果

Question

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

Result : 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);

Result : 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);

Result : 0

Ideally, sum of results for query 2 an 3 should be equal to result of query 1. Or there is some issue while comparing with NULL.

Answer 1

IN() can not handle NULL values. Instead use IS

and id is not NULL

or

and id is NULL