when insert persian character in oracle db i see the question mark

Question

I use the oracle with c#, i insert embedded in c# code , and my column(NVARCHAR2) and use N \'string\'. when insert in my machine that\'s correct and OK, but when run my app

Answer 1

in system variable enviroment I add NLS_LANG=AMERICAN_AMERICA.US8PC437 and my problem it's correct!