The following rules apply to the use of the DEFAULT function as part of the search condition within a HAVING clause:
- You can specify a DEFAULT function with a column name argument within a predicate. The system evaluates the DEFAULT function to the default value of the column specified as its argument. Once the system has evaluated the DEFAULT function, it treats it like a constant in the predicate.
- You can specify a DEFAULT function without a column name argument within a predicate only if there is one column specification and one DEFAULT function as the terms on each side of the comparison operator within the expression.
- Following existing comparison rules, a condition with a DEFAULT function used with comparison operators other than IS NULL or IS NOT NULL is unknown if the DEFAULT function evaluates to null.
A condition other than IS NULL or IS NOT NULL with a DEFAULT function compared with a null evaluates to unknown.
| DEFAULT Function Used with this Condition | Comparison Result |
|---|---|
| IS NULL |
|
| IS NOT NULL |
|
For more information about the DEFAULT function, see Teradata Vantage™ - SQL Functions, Expressions, and Predicates, B035-1145.