Average calculation Problem

Question

how can i apply the average calculation on a varchar column means only average the number values in that column and leave or return null if any character value comes in average
thanks

Answer 1

Hi,
Below is a conversion function, like Justin suggested.
Using this will be slower than a pure-SQL solution, so if Ankur's sulution works for you, you may want to stick with that.
CREATE OR REPLACE FUNCTION     to_num
(     in_txt          IN     VARCHAR2
,     in_non_num_val     IN     NUMBER     DEFAULT NULL
RETURN     NUMBER
DETERMINISTIC
IS
--     to_num attempts to convert in_txt into a number.  If it can,
--     then the value is returned.  If in_txt cannot be interpreted
--     as a number for any reason (e.g., it contains letters) then
--     in_non_num_val is returned.
--     to_num (NULL) returns NULL.
BEGIN
     RETURN     TO_NUMBER (in_txt);
EXCEPTION
     WHEN     OTHERS
     THEN
          RETURN     in_non_num_val;
END     to_num;
SHOW ERRORS