mysql> create table DemoTable1792
     (
     Name varchar(20)
     );
Query OK, 0 rows affected (0.00 sec)

mysql> insert into DemoTable1792 values('John Smith');
Query OK, 1 row affected (0.00 sec)
mysql> insert into DemoTable1792 values(NULL);
Query OK, 1 row affected (0.00 sec)
mysql> insert into DemoTable1792 values('David Miller');
Query OK, 1 row affected (0.00 sec)
mysql> insert into DemoTable1792 values(NULL);
Query OK, 1 row affected (0.00 sec)

mysql> select * from DemoTable1792;

+--------------+
| Name         |
+--------------+
| John Smith   |
| NULL         |
| David Miller |
| NULL         |
+--------------+
4 rows in set (0.00 sec)

mysql> select * from DemoTable1792 where Name IS NOT NULL;

+--------------+
| Name         |
+--------------+
| John Smith   |
| David Miller |
+--------------+
2 rows in set (0.00 sec)