Or maybe not! Here’s how you can do it.
There are other older and alternative drivers but I found the setup easiest with the latest Oracle and Microsoft software. And the latest version of SSDT can be installed alongside older software as well as develop backwards compatible SSIS and SSRS. Oh and schema and data compare are now built-in! So why are you waiting to upgrade?
Install SSDTSetup.exe file (this is the new 2016 SSDT software that includes visual studio 2015) found at https://msdn.microsoft.com/en-us/library/mt204009.aspx
Install SetupODTforVS2015.exe file found at Oracle’s download site.
Copy your tnsnames.ora and sqlnet.ora files to c:\program files (x86)\oracle developer tools for vs2015\network\admin\
When you start SSDT or just visual studio, to go Tools – Connect to Database – Change the data source to Oracle Database with Data provider of ODP.NET – Next. The Data source name should reflect the databases in your tnsnames.ora file if its setup correction. Just sign in as normal. It will then appear in your server “Server Explorer” tool under Data Connections.
You should end up at this screen with the ability to scroll through your tnsnames aliases and the rest should be obvious…
Gary Melhaff Data Warehouse Blog 