Oracle Database Discussions

Hi friends

I´m trying to load specific characters but i have the follow message error.

ORA-01756: quoted string not properly terminated

The character that i´m loading are

Á, Í, Ó, Ú, the É doesn't have problems...

if i change them but their lowercase á, í, ó, ú. I don´t have any problem.... I´m using character set UTF8

I looked into for ascii and i can´t found something for these characters

SQL> select chr('224') from dual;

C
-


SQL> select chr('233') from dual;

C
-


SQL> select chr('144') from dual;

C
-
É

Can anybody help me?
Thanks to all
Alex