Bind Operator to Function with optional parameter

Question

Hi,
as mentioned in the subject, I would like to create an operator which is bind to an function with an optional parameter:
CREATE OR REPLACE FUNCTION
          TS_Base_Func(iobject IN CIBase, format IN VARCHAR2 DEFAULT NULL) RETURN VARCHAR2 IS
BEGIN
     RETURN interval_object.IntervalToString(format);
END TS_Base_Func;
I can bind the operator with a VARCHAR2 as second parameter, but how can I bind an operator without the second parameter to this function?
Thanks!

Answer 1

What about using a "wrapper" function to implement what you would like to do? Here is a small sample:
SQL> CREATE OR REPLACE FUNCTION TEST
  2  (
  3          A       IN VARCHAR2
  4  ,       B       IN VARCHAR2     DEFAULT NULL
  5  )
  6  RETURN NUMBER
  7  AS
  8  BEGIN
  9          IF A = B THEN
10                  RETURN 1;
11          ELSE
12                  RETURN 0;
13          END IF;
14  END;
15  /
Function created.
SQL> CREATE OR REPLACE FUNCTION TEST_WRAPPER
  2  (
  3          A       IN VARCHAR2
  4  )
  5  RETURN NUMBER
  6  AS
  7  BEGIN
  8          RETURN TEST(A);
  9  END;
10  /
Function created.
SQL> CREATE OR REPLACE OPERATOR TestOperator
  2  BINDING (VARCHAR2)              RETURN NUMBER USING TEST_WRAPPER
  3  ,       (VARCHAR2, VARCHAR2)    RETURN NUMBER USING TEST;
Operator created.
SQL> SELECT  TestOperator(1) FROM DUAL;
TESTOPERATOR(1)
              0
SQL> SELECT  TestOperator(1,2) FROM DUAL;
TESTOPERATOR(1,2)
                0
SQL> SELECT  TestOperator(1,1) FROM DUAL;
TESTOPERATOR(1,1)
                1
SQL>The TEST_WRAPPER function has the signature you need for a one variable parameter. However, under the hood it calls the TEST function.