To use any of the following functions as the first argument of a method invocation, you must enclose the function in parentheses:
- DATE
- TIME
- VARGRAPHIC
For example, consider a structured UDT called datetime_record that has a DATE type attribute called start_date. The following statement invokes the start_date mutator method, passing in the result of the DATE function:
SELECT datetime_record_column.start_date((DATE)) FROM table1;