Some of my developer_id are in foreign language (special character). I googled how to handle those characters, and what people said was using

NVARCHAR2()

or use:

INSERT INTO table_name VALUES (N'你好');

However, I used NVARCHAR2() in stage and on all the tables but still doesn't work for me (the original datatype for developer_id was VARCHAR2()). Also, the insert statement with N at the beginning is not working for SQL Loader I think.

What should I do?

Here is where the problem shows:

Here is my ctl. file

Here is the datatype for all the data in the flat file:

The character set for the flat file is UTF-8. I thought I have successfully solved this problem by changing my Encoding when pre-loading the data to stage table, but the same problem still shows up when I finished importing my data to stage.