Question

I’m working on an attendence log, where I am using:

$sql="SELECT date FROM daily_entry_log_2011 WHERE logout_time > '16:30:00' AND  
logout_time < '18:30:00' AND date BETWEEN '".$firstdt."' AND '".$lastdt."' 
AND empid = '".$eid."'";

How can I check if logout_time is NULL in this query?

Answer 1

It really is not clear what you are exactly wishing to do. To test nullability use the IS NULL syntax : http://dev.mysql.com/doc/refman/5.0/en/comparison-operators.html#operator_is-null

The logout time can not both be ’18:30:00′ and null at the same time, so to hazard a guess, you are wanting

   WHERE ((logout_time > '16:30:00' AND logout_time < '18:30:00') OR logout_time) IS NULL) AND ...