DataTable Column DataTypes in OracleBulkCopy

I'm trying to use OracleBulkCopy to insert a large number of records from a DataTable into my database. Except, I'm not sure what DataTypes I have to use for the DataTable Columns. My database datatypes are varchar2, datetime and numeric. In the Oracle.DataAccess, I see Oracle.DataAccess.Client.OracleDBType and Oracle.DataAccess.Typ开发者_开发知识库es. What do I use for what?

I use the Oracle.DataAccess.Client.DbType enum for column datatypes when doing ArrayBinding for large insertion of data and this works correctly