Handling Date Format

Question

Hi Everyone,
I am using DB 11g and Apex 4.1 Versions.
We are working on a project where most of the time we would be uploading CSV through Apex and store the data in DB using some procedures developed by us and most of the time we get different date formats in the CSV which is sent by the client. It is the major issue which i encounter in my carrer.
Please suggest me how we can handle or tell the procedure to check if one format doesn't work take another if that also doesn't work go for another.
Any link or code or anything Please help me with this and make my career a bit more easy :)
Thanks,
Shoaib

Answer 1

Hi, Shoaib,
Shoaib581 wrote:
Thanks Guys,Pay particular attention to Paul's reply. The people who enter the data are the best people to make sure it is correct. Do whatever you can to ensure valid, consistent data entry. It may be hard for users who want to use their own favorite format, but not as hard as it is to correct mistakes later.
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Your clarification really helped me and made many things clear for me :). Any suggestion, how we can handle if the date format comes in below formats,
DD-MM-YY OR DD-MON-YY formats. Oracle forgives you if you use 'MON' where 'MM' was expected, so
TO_DATE ( '1-Dec-2012'
        , 'DD-MM-YYYY'
        )returns Decemer 1, 2012: it WILL NOT raise an error.
The converse is not true: TO_DATE (str, 'DD-Mon-YYYY') WILL raise an error if you the month part is '12'.
Here's a package function I wrote to try various formats in turn:
--          **   t o _ d t   **
--     to_dt attempts to convert in_txt to a DATE using in_fmt_1_txt.
--     If that fails, it tries again, using in_fmt_2_txt.
--     If that fails, it tries again, using in_fmt_3_txt, and so on.
--     As soon as one conversion works, the function returns the DATE,
--     and the remaining formats are not tried.
--     If all the formats given fail, then in_default_dt is returned.
FUNCTION     to_dt
(     in_txt          IN     VARCHAR2                    -- string to be converted
,     in_fmt_1_txt     IN     VARCHAR2     DEFAULT     'DD-Mon-YYYY'     -- 1st format to try
,     in_fmt_2_txt     IN     VARCHAR2     DEFAULT NULL          -- 2nd format to try
,     in_fmt_3_txt     IN     VARCHAR2     DEFAULT NULL          -- 3rd format to try
,     in_fmt_4_txt     IN     VARCHAR2     DEFAULT NULL          -- 4th format to try
,     in_fmt_5_txt     IN     VARCHAR2     DEFAULT NULL          -- 5th format to try
,     in_default_dt     IN     DATE          DEFAULT     NULL          -- Returned if nothing works
RETURN     DATE
DETERMINISTIC
IS
     fmt_cnt          PLS_INTEGER     := 5;          -- Number of in_fmt_ arguments
     fmt_num          PLS_INTEGER     := 1;          -- Number of argument being tried
     return_dt     DATE           := NULL;     -- To be returned
BEGIN
     FOR  fmt_num  IN  1 ..  fmt_cnt
     LOOP
          BEGIN     -- Block to trap conversion errors
               return_dt := TO_DATE ( in_txt
                                   , CASE     fmt_num
                                          WHEN  1     THEN  in_fmt_1_txt
                                          WHEN  2     THEN  in_fmt_2_txt
                                          WHEN  3     THEN  in_fmt_3_txt
                                          WHEN  4     THEN  in_fmt_4_txt
                                          WHEN  5     THEN  in_fmt_5_txt
                                END
               -- If control reaches this point, then TO_DATE worked
               RETURN     return_dt;
          EXCEPTION
               WHEN OTHERS
               THEN
                    IF  SQLCODE  BETWEEN -1865
                                  AND     -1839
                    THEN
                            NULL;
                    ELSE
                         RAISE;
                   END IF;
          END;     -- Block to trap conversion errors
     END LOOP;
     RETURN     in_default_dt;
END     to_dt
;Once again, this will convert a string like '12/11/10' to a DATE. It will not necessarily return the same DATE that was meant by whoever entered the string.