Error in Package containing function

Question

Hi, Here is my package that i am getting error - "PLS-00103: Encountered the symbol "=" when expecting one of the following"
create or replace package pre_pkg
is
FUNCTION FUN_DATE (a_date date)
RETURN number;
end pre_pkg;
create or replace package body pre_pkg
is
function FUN_DATE (a_date date)
return number
is
BEGIN
IF REGEXP_LIKE(a_date,'^\d{1}|d{2}/\d{1}|d{2}/\d{4} \d{2}:\d{2}:\d{2}.\d{3}$')
AND (REGEXP_INSTR(a_date,'[AP]M',1)=0
AND LENGTH(a_date) > 11
AND LENGTH(TRUNC(to_char(TO_TIMESTAMP(a_date,'MM/DD/YYYY HH24:MIS.FF'),'YYYY')))=4)
THEN
return := 0;
ELSIF REGEXP_LIKE(a_date,'^\d{1}|d{2}/\d{1}|d{2}/\d{4} \d{2}:\d{2}:\d{2} [AP]M$')
AND (REGEXP_INSTR(a_date,'[AP]M',1) > 0
AND LENGTH(TRUNC(to_char(TO_DATE(a_date,'MM/DD/YYYY HH:MIS AM'),'YYYY')))=4)
THEN
return := 0;
ELSIF REGEXP_LIKE(a_date,'^\d{1}|d{2}/\d{1}|d{2}/\d{4}$')
AND (REGEXP_INSTR(a_date,'[AP]M',1)=0
AND LENGTH(TRIM(a_date)) < 11
AND LENGTH(TRUNC(to_char(TO_DATE(a_date,'MM/DD/YYYY'),'YYYY')))=4)
THEN
return := 0;
ELSE
return := 1;
END IF;
EXCEPTION
WHEN OTHERS THEN
return := 1;
END FUN_DATE;
END pre_pkg;
Can any one help me in this regard. I am using oracle 10g.

Answer 1

Good practice for writing functions it so have a single exit point at the end of the function, rather than embedding return statements throughout it e.g.
create or replace package pre_pkg is
  FUNCTION FUN_DATE (a_date date) RETURN number;
end pre_pkg;
create or replace package body pre_pkg is
  function FUN_DATE (a_date date) return number is
    v_retval number;
  BEGIN
    IF REGEXP_LIKE(a_date,'^\d{1}|d{2}/\d{1}|d{2}/\d{4} \d{2}:\d{2}:\d{2}.\d{3}$')
       AND (REGEXP_INSTR(a_date,'[AP]M',1)=0
       AND LENGTH(a_date) > 11
       AND LENGTH(TRUNC(to_char(TO_TIMESTAMP(a_date,'MM/DD/YYYY HH24:MIS.FF'),'YYYY')))=4)
    THEN
      v_retval := 0;
    ELSIF REGEXP_LIKE(a_date,'^\d{1}|d{2}/\d{1}|d{2}/\d{4} \d{2}:\d{2}:\d{2} [AP]M$')
       AND (REGEXP_INSTR(a_date,'[AP]M',1) > 0
       AND LENGTH(TRUNC(to_char(TO_DATE(a_date,'MM/DD/YYYY HH:MIS AM'),'YYYY')))=4)
    THEN
      v_retval := 0;
    ELSIF REGEXP_LIKE(a_date,'^\d{1}|d{2}/\d{1}|d{2}/\d{4}$')
       AND (REGEXP_INSTR(a_date,'[AP]M',1)=0
       AND LENGTH(TRIM(a_date)) < 11
       AND LENGTH(TRUNC(to_char(TO_DATE(a_date,'MM/DD/YYYY'),'YYYY')))=4)
    THEN
      v_retval := 0;
    ELSE
      v_retval := 1;
    END IF;
    RETURN v_retval;
  EXCEPTION
    WHEN OTHERS THEN
      return := 1;
  END FUN_DATE;
END pre_pkg;
/Other things to note:
WHEN OTHERS exception is considered poor practice, especially if it doesn't raise an exception itself. Exception handlers should be written to cater for whatever exceptions you are expecting to happen, not a capture-all. Looking at your code, I wouldn't expect it to be raising any exceptions from the code itself.
Curiously, your function seems very odd. It looks like you are trying to validate that a date is valid, but by virtue of the fact that it's a DATE datatype it will (with very few exceptions e.g corrupt dates) be valid. The fact that you pass a DATE datatype as the first parameter of your REGEXP_LIKE functions means that it is doing an implicit conversion of that DATE datatype to a VARCHAR2 datatype based on your sessions NLS_* settings, which could vary and cause your function to fail in other sessions. If the date were actually being passed into the funciton as a string (varchar2) then there are simpler ways to validate whether it's a valid date or not, simply by trying to turn the string into a DATE datatype and capturing the exception for invalid dates.