SQL ODBC driver for NAV 2015

you can use SQLOLEDB provider to make a connection (ADODB.Connection), means connect to the sql db from outside.

other options
- microsoft query
- powerpivot
- jetreports

or use third party tools
https://visualstudiogallery.msdn.microsoft.com/f95fe458-5042-49a3-b4fb-668708eaffcd
http://www.cdata.com/odbc/

you could also use the nav web services (soap or odata) to connect nav. best way, uses the nav business logic.

for connecting e.g. excel docs via odbc from within nav follow
https://moxie4nav.wordpress.com/2015/09/12/export-data-to-excel-using-odbc-in-nav-20132015/