Nulls are special values of the data types supported by workflow system.
Following are brief descriptions of the functions that can be used with null values.
Function | What it does |
---|---|
null() | Returns a null time value. |
is_null() | Returns the Boolean value true if the expression evaluates to a null value. |
NULL_INT_VALUE_TEMPLATE | Returns the Integer value -1543210987. |
NULL_STRING_VALUE_TEMPLATE | Returns the String value <<null>>. |
This time function returns a null time value. The only valid operations you can perform on null variables using null() are assignments and equality comparisons for Time data type.
null(time)
where time is the data type. Time is
the only supported data type for this function.This Boolean function returns true if the input expression evaluates to a null value; otherwise, the is_null function returns false. The only valid operations you can perform on null variables using is_null() are assignments and equality comparisons for Time data type.
is_null(time_expr)
where time_expr is an
expression of type time.