SQL删除值包括NULL

Question

我想将所有没有备注的记录删除为"无效进程"和其他2个条件,如下代码: -

 DELETE FROM Entry WHERE EmployeeId = 474 AND Entry_Date = '2016-10-01' 
 AND Remarks <> 'Invalid Process'

但问题是它不会删除具有NULL值的记录.我想删除除备注之外的所有内容为"无效进程".

Answer 1

添加IS NULL条件.<>操作员无法检查NULL值

 DELETE FROM Entry WHERE EmployeeId = 474 AND Entry_Date = '2016-10-01' 
 AND (Remarks <> 'Invalid Process' or Remarks IS NULL)