Apart from Drupal most organisations may have many systems such as a CRM, HR and e-commerce system. The field of Business Intelligence (BI) deals with bringing disparate data sources into a single data warehouse(DW). If you wanted to display data from your DW using Drupal, the Views module is a good place to start. Before you can use the Views module you need to connect to the database and describe the tables to Views. I am a SQL developer so I am reluctant to write my own module. I found there are several modules that enable me to show external data in Views:
With Drupal 8 around the corner I decided to try out the only module that has a Drupal 8 version at the time of writing, the VDC module. Using the Chinook database I use as a sample database I was able to achieve my goal quite easily.
I already had Views installed my site so I just had to download and enable VDC.
I installed the Chinook database as a separate from my Drupal database. Then added a connection which looked like this in my settings.php file: