How to handle infinity in PL/SQL ?

Question

my function is returning a/b
a,b are number
retrun type is number...
how to deal with it ?

Answer 1

returning a Binary_float will do that, yes.
But the same is true for the original function. It only does an implicit datatype conversion to a binary_float.
strange result, btw
SQL> CREATE OR REPLACE FUNCTION TEST_FUNC
  2  (
  3          a       IN NUMBER
  4  ,       b       IN NUMBER
  5  )
  6  RETURN BINARY_FLOAT
  7  AS
  8  BEGIN
  9     RETURN a/b;
10  EXCEPTION
11          WHEN ZERO_DIVIDE THEN
12                  RETURN 'infinity';
13  END;
14  /
Function created.
SQL>
SQL>
SQL> select to_char(test_func (1, 1.1), 'tm')
  2    from dual
  3  /
TO_CHAR(TEST_FUNC(1,1.1),'TM')
.909090936
SQL>
SQL> CREATE OR REPLACE FUNCTION TEST_FUNC
  2  (
  3          a       IN NUMBER
  4  ,       b       IN NUMBER
  5  )
  6  RETURN BINARY_FLOAT
  7  AS
  8  BEGIN
  9     RETURN to_binary_float (a)/to_binary_float (b);
10  END;
11  /
Function created.
SQL>
SQL>
SQL> select to_char(test_func (1, 1.1), 'tm')
  2    from dual
  3  /
TO_CHAR(TEST_FUNC(1,1.1),'TM')
.909090877both have less precision compared to using numbers...