mysql中查詢字段為null或者不為null的sql語句怎么寫？

在mysql中，查詢某字段為空時，切記不可用 = null，
而是 is null，不為空則是 is not null

select * from table where column is null;

select * from table where column is not null;

select * from s_class_log WHERE class_uuid="50f3b8ecde184f22ac6bd7304b388b60" AND course_schedules_uuid="940991bff18d4122a4a6471b61ef18f2" and  remark_status is not null