Nulls and DateTime and Interval Data
The general rule for managing nulls with DateTime and Interval data environments is that, for individual definitions, the rules are identical to those for handling numeric and character string values.
|
WHEN any component of this type of expression is null … |
THEN the result is … |
|
Value |
null. |
|
Conditional |
FALSE. |
|
CASE |
as it would be for any other CASE expression. |
DateTime or Interval values are defined to be either atomically null or atomically non-null. For example, you cannot have an interval YEAR TO MONTH value in which YEAR is null and MONTH is not.