Having Problem with Oracle and C#.NET

Question

I am doing gui interface for oracle as a part of 5th sem project in C#.NET and backend as oracle. problem1)My problem is when i fetch data from the oracleDataAdapter there are some junk values shown in the datagrid ->I think that windows use unicode and Oracle uses ascii encoding technique. problem 2)--Whenever i update my dataadapter from the application only 2 or 3 characters are entered in the oracle table. -> Encoding class is provided by the .NET which is cumbersome problem 3)--The command builder also dosent works as it gives error : dynamic generation of SQL is not supported for table which do not return any key column information ->Is there any other way ? , else i have to manually write the insert ,update and the delete query . I use only the system.data.oracleclient; namespace will using the oracle.dataaccess namespace work ?