To Check Value in Range

Question

I have three columns in a table with data type varchar2
one in of min_range and other is of max_range both are defined user will enter only the result value against a test
now i want to check that result value
firstly if number then must be in min and max range otherwise change the record visual attribute.If the result entered is character then no check

Answer 1

One way to do it would be to test if you can convert the value to a number,
use the pl/sql block example as a guide,
DECLARE
FUNCTION Is_Number
(vchar_value VARCHAR2)
RETURN BOOLEAN IS
tst_num NUMBER;
BEGIN
tst_num := To_Number (vchar_value);
RETURN True;
EXCEPTION
WHEN VALUE_ERROR THEN
RETURN False;
END;
BEGIN
IF Is_Number ('45') THEN
dbms_output.put_line ('Value is a number');
END IF;
IF NOT Is_Number ('ABC') THEN
dbms_output.put_line ('Value is not a number');
END IF;
END;