ODP.NET is the best way to connect to the Oracle database. For information about ODP.NET, see: http://www.oracle.com/technology/global/cn/tech/windows/odpnet/odp. Net-fov.html download address: http://www.oracle.com/technology/global/cn/software/tech/windows/odpnet/index.html I use 9.2. Using ODP.NET development web projects, it is very simple to deploy, you don't need to install Oracle Client on the server, just install ODP.NET. Then you can match the data connection. This is successful on the Windows 2000 operating system. It can be connected to Oracle 9i and Oracle 8i, which is quite convenient for us. On the Windows 2003 system, the connection will report an error: "Unable to load dll (ORAOPS9.DLL)", Chinese report error: "Unable to load DLL (ORAOPS9.DLL)", because Windows 2003 is high than 2000, Leading the DLL that cannot be read, the solution: put the bin directory in the ODP.NET installation directory, set to ASP.NET with read / write permissions, or read the everyone to read and write permissions, remember, then restart the machine. This will be accessed. This "unable to load dll (ORAOPS9.DLL)" "Unable to load the DLL (ORAOPS9.DLL)" error, only in 2003, even if the Oracle Client 9i client is installed, it must set the permissions. Oh! ! Good luck !!