SQL & PL/SQL :: Convert Data Back To Special Character Values?

Enterprise Edition Release 10.2.0.5.0

SQL> SELECT * FROM NLS_DATABASE_PARAMETERS where parameter = 'NLS_CHARACTERSET';
PARAMETER VALUE
------------------------------ ----------------------------------
NLS_CHARACTERSET AL32UTF8
SQL>

There is table (VIN_TEMP) in my company database containing following records. It seems like this table should contain some greek language special chracter values instead of this weird data.

SQL> select * from vin_temp;
ATTR
--------------------------------------------------------------------------------
���9999
���9998
���9997
���9997

[code]....

Client are reporting these records as invalid and requesting us to fix. As i investigated i found out, this table was created and loaded few year back. Client sent us one time files which we loaded into this table. I was able to find the code which was actually used to load this table, but unfortunately i was not able to find the raw files where we load this data from...

It seems like Previous Developer specified character set "UTF8" statement, in his sql loader script, to load this data. It seem those file contain some Greek language special character data which was not support by "UTF8" charater set and result in creating those invalid data. My Job is to fix these invalid records and convert them back to its original values which were present in the raw file. I tried to contact client and see if i can find out the raw files but no luck. I tried to use convert function as mention to convert this data from "UTF8" to our current character set format but no luck.

SQL> SELECT attr, dump(attr), convert(attr,'UTF8', 'AL32UTF8') from vin_temp;
ATTR DUMP(ATTR) CONVERT(ATTR,'UTF8','AL32UTF8'
------------------ ---------------------------------------------------------------- -----------------------------
���9999 Typ=1 Len=13: 239,191,189,239,191,189,239,191,189,57,57,57,57 ���9999
���9998 Typ=1 Len=13: 239,191,189,239,191,189,239,191,189,57,57,57,56 ���9998
���9997 Typ=1 Len=13: 239,191,189,239,191,189,239,191,189,57,57,57,55 ���9997
���9997 Typ=1 Len=13: 239,191,189,239,191,189,239,191,189,57,57,57,55 ���9997

[code]....

Here is the script to create table with those type of invalid records.

create table VIN_TEMP
(
attr VARCHAR2(50 CHAR)
);
insert into VIN_TEMP (attr) values ('���9999');
insert into VIN_TEMP (attr) values ('���9998');

[code]....