ERROR divisor is equal to zero

INSERT INTO table2
(
SELECT aa,bb,cc,
bb / package1.function1 (cc,dd )
FROM table2
where aa = 5
)
-- ERROR

-- ORA-01476: divisor is equal to zero

-- package1.function1 (cc,dd ) is a very expensive function
(time wise)
-- and I could also put it in the where clause but it will
double the time.
-- I could put it in a case statement in the select
-- but that is the same problem

-- is there a way of checking the result of
package1.function1()
-- and excluding it from the select statement without
retrieving it twice.

.

Relevant Pages