C# Oracle Connection without Client // missing dll


I'm trying to connect with Visual Studio 2019 and C# to Oracle without OracleClient. I downloaded the ODAC xcopy 32 bit and copied to the debug folder. After that, I referenced the Oracle.DataAccess.dll.

When I tried to run the Application at another PC, I got following error:

System.DllNotFoundException: DLL "OraOps19.dll" - HRESULT 0x8007007E

I already tried to install the dll over regsvr, but it didn't work.

Thank you

asked on Stack Overflow Jul 22, 2020 by Tobias • edited Jul 22, 2020 by Long Luong

2 Answers


Option - A. Connect to Oracle Database from Visual Studio Open Visual Studio after ODT installation. Right click on Server Explorer's root node and choose "Create New Connection".

In the connection dialog, click the "Change" button to change the data source.

Select "Oracle Database" from the list of data sources and "ODP.NET, Managed Driver" from the drop down list. If you do not see it, the installation of Oracle Developer Tools for Visual Studio was not successful. Do NOT select ".NET Framework Data Provider for Oracle".

You will now see Oracle's connection dialog:

Enter the user name and password.

In the connection type drop down, choose "Basic" or "EZ Connect".

Enter the host name/IP, port number, and service name for the database you wish to connect to.

Press OK to connect.

You can now explore your Oracle Database in Server Explorer and take advantage of many of the Oracle Developer Tools for Visual Studio features.

Option - B : Unable to load OraOps.dll / Solution / Workaround / Hints / Diagnosis. Unable to load DLL “OraOps10.dll”

answered on Stack Overflow Jul 22, 2020 by Nadeem Taj

If you don't want to install any Oracle client then the only way (apart from some 3rd party drivers) is to install the ODP.NET, Managed Driver

You can download it from the Oracle website

answered on Stack Overflow Jul 22, 2020 by Wernfried Domscheit

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