问题
I am trying to upgrade my existing application built on ODP.NET 11g to ODP.NET 12c in the hope that it'll improve performance of database calls and data retrieval. In this regard, I installed the latest ODP.NET 12c and changed all Oracle project references to point to the latest Oracle.ManagedDataAccess.dll instead of Oracle.DataAccess.dll.
While the project builds successfully, I'm seeing an exception, "Unsupported column datatype" being thrown from the ExecuteReader method when trying to retrieve data. Sadly, there's no ORA code associated with the exception for me to search further.
Does anyone know if certain datatypes are supported with the manageddataaccess.dll? It seems to work if I replace it with its unmanaged version (Oracle.ManagedDataAccess.dll).
回答1:
Edit: As of ODAC 12c Release 3 (released Dec. 2014) XMLType is now supported in ODP.NET, Managed Driver. Please upgrade if you are hitting issues like the one mentioned here.
Please note that there is also a 12c version of Oracle.DataAccess.dll (ODP.NET, Unmanaged Driver)
Are you using XMLType in the database? That is one of the things that is not yet supported by the ODP.NET, Managed Driver. At the time of this writing, feature areas with no managed driver support or very limited support include user-defined types, XMLDB features and datatypes, Oracle Advanced Queuing, the client result cache, bulk copy, and the Transaction Guard feature of Oracle Database 12c.
http://docs.oracle.com/html/E41125_02/intro004.htm
As time goes on, more datatypes and features will be supported, so always download new releases, then check that section of the new documentation as well as the "What's New" section to find out what has been added.
来源：https://stackoverflow.com/questions/25489730/unsupported-column-datatype-odp-net