Null Conditions
A NULL condition tests for nulls. This is the only condition that you should use to test for nulls.
                  
null_condition::=
Table 6-9 lists the null conditions.
Table 6-9 Null Condition 
| Type of Condition | Operation | Example | 
|---|---|---|
| IS [NOT] NULL | Tests for nulls. See Also: Nulls | SELECT last_name FROM employees WHERE commission_pct IS NULL ORDER BY last_name; | 
